Abstract:
A workpiece container assembly includes a container, and a cover having a locking section that facilitates manipulation and gripping by an apparatus for opening and closing the workpiece container assembly. The container is configured to accommodate workpiece(s) therein. A body of the cover covers an open side of the container. The locking section of the cover includes a bar protruding towards the exterior of the body of the cover, a jaw extending from the bar, and a resilient member connected to the bar such that the bar is biased in its longitudinal direction. The container also includes a frame defining an insertion hole into which the bar of the locking section of the cover is inserted. The opening/closing apparatus includes a clamp that can latch onto the jaw and move the bar against the biasing force of the resilient member to withdraw the bar from the insertion hole in the frame of the container.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a workpiece container assembly and to an apparatus for opening/closing the container of the assembly. More particularly, the present invention relates to a container assembly for accommodating semiconductor wafers in the course of their being processed, and to an apparatus for opening and closing a cover of the container assembly. 
   2. Description of the Related Art 
   Semiconductor devices are fabricated by subjecting a wafer to various manufacturing processes, such as photolithography, deposition, etching, and thin film-forming processes. These wafers are typically 8 inches in diameter. The wafers are accommodated in a container and from there are introduced into the manufacturing apparatus in which the above-mentioned processes are carried out. As the technology behind these processes has improved, wafers having a diameter of 12 inches are being used in addition to the 8-inch wafers. 
   An open wafer cassette is mainly used to accommodate the wafers when the wafers have a diameter of 8 inches. Recently, however, a closed-type of container assembly, for example, a front open unified pod (hereinafter, simply referred to as a “FOUP”) has been developed for use with the larger 12-inch wafers. The FOUP is better than an open wafer cassette in preventing the wafers from being contaminated when the wafers are transferred to and from the manufacturing apparatus. 
   The FOUP includes a container in which the wafers are accommodated, and a cover disposed over the front of the container. In addition, a separate opening/closing apparatus is used to remove the cover from the container. An example of such a FOUP is disclosed in U.S. Pat. No. 6,186,331 issued to Kinpara, et al. 
   Hereinafter, a conventional FOUP and an apparatus for opening/closing the FOUP will be described with reference to  FIGS. 1 and 2 . 
   The FOUP  10  includes a container  12  for accommodating wafers therein, and a cover  14  covering an open side of the container  12  so as to close the container  12 . The container  12  also has opposite sidewalls which define therein a series of parallel slots  16 . The wafers W are inserted into the slots  16 , respectively. On the other hand, the cover  14  includes a main cover body, and a locking section  18 . The container  12  has a frame  30  which cooperates with the locking section  18  so that the cover  14  may be attached to and detached from the container  12 . 
   Referring to  FIG. 2 , the locking section  18  includes a plate  20  that is rotatably supported within the body of the cover  14 . The rotatable plate  20  has a keyhole  22  in the center thereof. The keyhole  22  is exposed at the front of the cover  14  such that a key can be inserted into the keyhole  22  from outside of the cover  14 . When a user rotates the key after inserting the key into the keyhole  22 , the plate  20  is rotated. 
   The locking section  18  of the cover  14  also includes a pair of bars  24 . First ends of the bars  24  are connected to the rotatable plate  20 , and second ends of the bars  24  protrude from the body of the cover  14  through upper and lower surfaces of the cover  14 , respectively. A respective inlet hole  26  extends through each of the upper and lower surfaces of the cover  14  to allow the bars  24  to protrude from the cover  14 . 
   The frame  30  is integral with the container  12  and has insertion holes  32  (shown in  FIG. 1 ) which are positioned across from inlet holes  26  of the cover  14  so as to receive the bars  24  of the cover  14  when the cover  14  is attached to the container  12 . That is, the bars  24  of the locking section  18  are inserted into the insertion holes  32  formed in the frame  30  so that the cover  14  is coupled to the container  12 , thereby closing the FOUP  10 . 
   The FOUP  10  having the above structure requires a separate opening/closing apparatus for operating the cover  14  to open/close the container  12 . 
   Generally, the opening/closing apparatus includes a loading section which supports the FOUP  10  and is operable to move the FOUP  10  horizontally, a plate that will face the cover of a FOUP  10  supported by the loading section, a key mounted on a side of the plate so as to be insertable into the keyhole  22  of the FOUP, and a drive mechanism for moving the plate vertically or horizontally. One example of such a FOUP opening/closing apparatus is disclosed in U.S. Pat. No. 6,053,688 (issued to Cheng). 
   Next, the operation of the FOUP opening/closing apparatus will be described. 
   First, a closed FOUP  10  accommodating a plurality of wafers to be processed is placed on the loading section. Then, the FOUP  10  is moved horizontally towards the plate until the plate and the cover  14  engage each other. At this time, the key mounted on the plate is inserted into the keyhole  22  in the front of the cover  14 . 
   Subsequently, the key is rotated. As a result, the plate  20  is rotated and the bars  24  connected to the rotating plate  20  are moved vertically so that second ends of the bars  24  are withdrawn into the cover  14 . Accordingly, the cover  14  can be separated from the container  12 . In addition, since the key is inserted into the keyhole  22 , the cover  14  is attached to the plate. 
   Then, the plate to which the cover  14  is attached is moved horizontally to detach the cover  14  from the container. The plate is then moved vertically so as to open the FOUP  10 . 
   However, the keyhole  22  formed in the cover of the conventional FOUP  10  is very small and thus, the key of the opening/closing apparatus is also very small. Accordingly, the key cannot be precisely aligned with the keyhole  22  when the cover  14  of the FOUP  10  is to be separated from the container  12 . Therefore, sometimes the FOUP  10  is not be opened. 
   In addition, the FOUP  10  is frequently opened/closed during the semiconductor manufacturing process and hence, the key is frequently inserted into the keyhole  22  and is rotated while in the keyhole  22 . For this reason, the keyhole  22  becomes enlarged, and eventually a gap is formed between the key and the keyhole  22 . If a large gap is formed between the key and the keyhole  22 , the opening/closing apparatus may not be able to rotate the key within the keyhole  22 . In this case, an opening/closing error of the FOUP  10  occurs. As a result, the processing time is increased and the productivity of the semiconductor manufacturing process is correspondingly decreased. 
   SUMMARY OF THE INVENTION 
   An object of the present invention is to obviate the problems of the prior art. Therefore, it is a first object of the present invention to provide a workpiece container assembly whose cover has a locking section that facilitates the opening/closing of the cover. A second object of the present invention is to provide an apparatus for opening/closing the workpiece container assembly. 
   A still further object of the present invention is to provide a workpiece container assembly whose cover has a locking section, in combination with an apparatus having a cover-separating section that can simultaneously manipulate the locking section of the cover and grip the cover to open/close the workpiece container assembly. 
   The workpiece container assembly may be a FOUP configured to accommodate 12-inch semiconductor wafers. 
   The container assembly includes a container for accommodating workpiece(s) therein, and a cover for covering the container. The container has an opening at one side thereof, and a frame delimiting the opening and having an insertion hole therein. The cover has a cover body that spans the opening of the container, and a locking section that includes a bar protruding towards an exterior of the body of the cover and a resilient member connected to the bar such that the bar is biased longitudinally into the insertion hole in the frame of the container. 
   A jaw extends from the bar to the exterior of the body of the cover. The jaw is preferably tapered so as to define a notch therein. 
   The apparatus for opening/closing the container assembly includes a loading section having a stage dedicated to support the container assembly, and a plate assembly extending upright relative to the stage and positionable in opposition to the cover of a container assembly disposed on the stage of the loading section, the plate assembly having a cover-separating section including a clamp for unlocking the cover from the container and gripping the unlocked cover. 
   The clamp is operated to engage the jaw extending from the bar of the locking section and move the bar against the biasing force of the resilient member to withdraw the bar from the insertion hole in the frame of the container. The clamp also latches onto the jaw, using the notch in the jaw, so that the cover can be removed form the opening of the container once the locking section has been unlocked. 
   The locking section of the workpiece container assembly can be manipulated using the simple operation of a clamp. In this way, there is a wide margin for positioning of the cover-separating section of the opening/closing apparatus relative to the cover of the container assembly, and the manipulation of the locking section by the cover-separating section hardly causes the locking section to wear in such a manner that it becomes difficult to open and close the cover. Accordingly, few processing errors ever arise as the result of the continued us of the container assembly and opening/closing apparatus of the present invention. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiments thereof made with reference to the attached drawings, of which: 
       FIG. 1  is a perspective view of a conventional FOUP; 
       FIG. 2  is a perspective view of part of a locking section of the conventional FOUP; 
       FIG. 3  is a perspective view of a FOUP according to the present invention; 
       FIG. 4  is a perspective view of a locking section of the FOUP according to the present invention; 
       FIGS. 5A and 5B  are sectional views of the FOUP according to the present invention; and 
       FIGS. 6A and 6B  are sectional views of an apparatus for opening/closing a FOUP according to the present invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   A FOUP  100  according to the present invention will now be described in detail with reference to  FIGS. 3–5B . 
   Referring first to  FIG. 3 , the FOUP  100  includes a container  102  having an opening at one side thereof, and a cover  104  disposed over the opening for closing the container  102 . The open side of the container  102  will be referred to hereinafter as the front of the container  102 . 
   The container  102  is configured to accommodate a plurality of wafers therein. More specifically, the container  102  has opposite sidewalls in which a series of parallel slits  102   a  are defined. The wafers are received in the slits  102   a , respectively. 
   The cover  104  has a cover body that spans the opening at the front of the container  102 , and at least one locking section  106  (refer to  FIG. 4 ) for securing the cover  104  to the container  102 . The locking section  106  includes a bar  200  protruding from the body of the cover  104 , and a resilient member  204  connected to the bar  200 . In addition, the container  102  has a frame  110  extending around and thus delimiting the opening at the front of the container  102 . The frame  110  also defines an insertion hole  108  into which the bar  200  is inserted. 
   The bar  200  is biased into the insertion hole  108  by the resilient member  204  of the locking section  106  to keep the cover  104  secured to the container. On the other hand, the cover  104  may be separated from the container  102  by withdrawing the bar  200  from the insertion hole  108  against the force exerted by the resilient member  204 . 
   The locking section  106  and the frame  110  will be described in more detail below. 
   Referring still to  FIGS. 3 and 4 , a resilient member  204  is connected to the second end of the bar  200 . The resilient member  204  extends in the longitudinal direction of the bar  200 . Thus, when a longitudinal force is applied to the bar  200  to compress the resilient member  204 , the first end of the bar  200  is retracted into the body of the cover  104 . 
   The cover  104  also includes a supporting member  206  connected to one end of the resilient member  204  for supporting the resilient member  204 . The supporting member  206  extends within the body of the cover  104  in a direction perpendicular to the direction in which the bar  200  is free to move. Accordingly, the supporting member  206  allows the resilient member  204  to be compressed when an external force is applied to the bar  200 . 
   When the cover  104  is fitted into the opening at the front of the container  102 , the insertion hole  108  in the frame  110  of the container  102  confronts the inlet hole  202  in the body of the cover  104 , respectively. Accordingly, the first end of the bar  200  extending from the body of the cover  104  will be inserted into the insertion hole  108  of the frame  110 , whereby the cover  104  is locked to the container  102 . 
   In addition, the front of the body of the cover  104  has a hole  212  therethrough that exposes a portion of the bar  200 . The locking section  106  further includes a jaw  210  extending horizontally from the bar  200  through the hole  212 . Thus, an external force can be securely applied to an upper or lower surface of the jaw  210  in the longitudinal direction of the bar  200 . Such an external force is transferred to the bar  200 , whereby the resilient member  204  connected to the bar  200  can be compressed, the bar  200  is retracted, and the cover  104  is released from the container. That is, the first end of the bar  200  is withdrawn from the insertion hole  108 , so the cover  104  can be separated from the container  102 . 
   To facilitate this operation, the length of the hole  212 , as taken in the longitudinal direction of the bar  200 , is larger than the distance that the first end of the bar  200  protrudes into the insertion hole  108  in the frame  110  of the container  102 . Preferably, the length of the hole  212 , as taken in the longitudinal direction of the bar  200 , is larger than the distance that the first end of the bar  200  protrudes form the inlet hole  202 . Accordingly, the first end of the bar  200  can be retracted into the body of the cover  104  to release the cover  104  from the container  102 . 
   In addition, the jaw  210  is tapered towards the bar  200  such that the cross-sectional area of that portion of the jaw  210  adjacent the bar  200  is smaller than the cross-sectional area of a distal end portion of the jaw  210 . 
   Still further, the locking section  106  may include a second protrusion extending from the bar  200  and through the hole  212  in the body of the cover  104 , adjacent and opposite to the jaw  210 . As shown in the drawings, the protrusion may serve as a stop for the bar  200  by abutting an edge of the body of the cover  104  that defines an end of the hole  212  in the longitudinal direction (direction of movement) of the bar  200 . The second protrusion may thus serve to position the jaw  210  relative to a clamp of the opening/closing apparatus (described later). 
   The cover  104  may also have more than one locking section  106 . For instance, the cover  104  may have locking sections  106  that are longitudinally aligned. In this case, the bars  200  of the locking sections  106  extend in opposite directions, i.e., from the interior of the cover  104  to upper and lower surfaces of the cover  104 , respectively. In addition, the cover  104  may have locking sections  106  that are disposed in parallel. In this case, the bars  200  of the locking sections  106  are laterally spaced from and extend parallel to one another. In either case, the frame  110  of the container has a plurality of insertion holes  108  that receive the bars  200  of the locking sections  106 , respectively. 
   As shown best in  FIG. 3 , the present embodiment employs four locking sections  106 . The two bars  200  of a first pair of the locking sections  106  extend towards the upper surface of the cover  104  and the two bars  200  of the other pair of locking sections  106  extend towards the lower surface of the cover  104 . The frame  110  of the container  102  thus has four insertion holes  108  that receive the bars  200 , respectively, so that the cover  104  can be secured stably on the container  102 . 
   That is, as shown in  FIG. 5A , respective bars  200  of locking sections  106  of the FOUP  100  protrude through upper and lower surfaces of the body of the cover  104 , respectively. Accordingly, one end of each bar  200  is received in an insertion hole  108 , so that the FOUP  100  is closed. 
   On the other hand, referring to  FIG. 5B , the bars  200  of the locking sections  106  of the FOUP  100  may be withdrawn into the body of the cover  104  through the upper and lower surfaces of the body of the cover  104 . That is, the bars  200  may be withdrawn from the insertion holes  108 . In this case, the cover  104  can be separated from the container  102  so that the FOUP  100  can be opened. 
     FIGS. 6A and 6B  show an apparatus for opening/closing the FOUP according to the present invention.  FIG. 6A  shows a state in which the cover  104  is coupled to the container  102 , and  FIG. 6B  shows a state in which the cover  104  has been separated from the container  102  by the apparatus. 
   In general, the FOUP opening/closing apparatus is disposed at a boundary between semiconductor processing equipment requiring a highly pure environment and a high vacuum state, and a semiconductor line in which such conditions are maintained at a much lower level. As soon as the cover of the FOUP is opened by the FOUP opening/closing apparatus, the container of the FOUP is mounted on the semiconductor processing equipment. Accordingly, the wafers accommodated in the FOUP are not exposed to the environment present in the semiconductor line while the semiconductor manufacturing process is being carried out by the semiconductor processing equipment. 
   Referring to  FIGS. 6A and 6B , the FOUP opening/closing apparatus  300  has a loading section  302  onto which the FOUP  100  is loaded. In more detail, the loading section  302  includes a stage  302   a  for supporting the FOUP  100  thereon and a driving mechanism  302   b  for moving the stage  302   a  horizontally. In particular, the driving mechanism  302   b  moves the stage  302   a  horizontally towards a door of the semiconductor processing equipment. At this time, the cover  104  of the FOUP faces the door of the semiconductor processing equipment. 
   The FOUP opening/closing apparatus  300  also includes a plate assembly  304  and a drive mechanism  308  for moving the plate assembly  304  to a position confronting the cover  104  of a FOUP  100  that has been placed on the loading section  302 . That is, the plate assembly  304  is positioned adjacent and upright relative to the stage  302   a  of the loading section. The plate assembly  304  is also located adjacent and opposite the door of the semiconductor processing equipment. 
   The plate assembly  304  has a cover-separating section  306  for physically detaching the cover  104  from the container  102  of the FOUP  100 . To this end, the cover-separating section  306  is disposed at one side of the plate assembly  304  opposite to the cover  104  of the FOUP  100 . The cover-separating section  306  comprises a clamp  400  that applies force to the bar  200  in a longitudinal direction of the bar  200  to thereby detach the cover  104  from the container  102  of the FOUP  100 . In the present embodiment, the clamp  400  of the cover-separating section  306  simultaneously applies longitudinal forces to the bars  200  of all of the locking sections  106  of the cover  104 . More specifically, the clamp  400  operates to move the first ends of bars  200  into the body of the cover  104 , so the cover  104  can be separated from the container  102  of the FOUP  100 . To this end, the number of arms  400   a  of the clamp  400  corresponds to the number of bars  200  of the FOUP  100 . 
   In addition, the clamp  400  grips the cover  104  after it has been detached from the container  102  so that the freed cover  104  is basically attached to the cover-separating section  306 . To this end, the clamp  400  is configured to grip the protruding jaw or jaws  210  that extend from the bar(s)  200  of the cover  104 . In addition, the opening/closing apparatus  300  has a driving mechanism  402  connected to the arms  400   a  of the clamp. The driving mechanism  402  is operable to move the arms  400   a  toward and away from each. Like any of the driving mechanisms of the present invention, the driving mechanism  402  may comprises a motor and transmission elements for converting a rotary output of the motor to linear motion. The form of the clamp  400  of the cover-separating section  306  depends on the number and shape of the jaws  210  of the FOUP  100 . Hereinafter, the clamp  400  will be described in more detail with reference to the embodiment of the FOUP described above in accordance with the present invention. 
   That is, as was described above, the FOUP  100  includes two pairs of locking sections  106 , wherein each pair includes longitudinally aligned bars  200  that extend in opposite directions towards upper and lower surfaces of the body of the cover  104 . Two protrusions, including one jaw  210 , extend from each bar  200  as spaced from one other along the length of the bar  200 . The jaw  210  is tapered towards the bar  200  so as to define a notch that will receive the distal end of an arm  400   a  of the clamp  400 . That is, the distal end of each arm  400   a  has a shape corresponding to the notch in a respective one of the jaws  210 , whereby the arms  400   a  mesh with the jaws  210 . 
   The arms  400   a  of the clamp  400  are thus latched over the jaws  210  protruding from the bars  200  that extend towards the upper and lower surfaces of the body of the cover  104 , respectively. In particular, each arm  400   a  of the clamp  400  is inserted into a space formed between a jaw  210  and the corresponding protrusion extending from the bar  200  which together allow the bar  200  to be stably moved by the clamp  400 . Then, the driving mechanism  402  moves the arms  400   a  toward each other, whereby the bars  200  are withdrawn from the insertion holes  108  in the container  102 , and into the body of the cover  104 . 
   The driving mechanism  308  is operable to move the plate assembly  304  in both the vertical and horizontal directions, to thereby align the cover-separating section  306  with the locking section  106  of the cover  104 . Therefore, once the cover  104  is gripped by the clamp  400  of the cover-separating section  306 , the plate assembly  304  is moved horizontally and then vertically to remove the cover  104  from the open side of the container  102 . Accordingly, the interior of the container  102  of the FOUP  100  is open to the door of the semiconductor processing equipment. 
   Note, however, the opening/closing operation can be performed even when the clamp  400  is not precisely aligned with the jaws  210  by the driving mechanism  308 . In this case, the location of the arms  400   a  of the clamp  400  are merely adjusted relative to each other. That is, a precise positioning of the cover-separating section  306  relative to the container assembly  100  is not required before the cover  104  can be removed form the container  102 . 
   As described above, the bar is biased by the resilient member and can be moved without the use a key and a key hole when detaching the cover from the container. Accordingly, the present invention provides for a wide margin for aligning the locking section of the cover with the cover-separating section of the apparatus for opening/closing the container assembly. In addition, any wearing of the engaged parts of the locking section and cover-separating section will not affect the ability of the operation to be easily carried out. Thus, the opening/closing operation will not cause a reduction in the productivity of the semiconductor device manufacturing process. 
   Although the present invention has been described in detail with reference to the preferred embodiments thereof, various changes, substitutions and alterations of these preferred embodiments will become apparent to those of ordinary skill in the art. All such changes, substitutions and alterations can be made to the disclosed embodiments without departing from the true spirit and scope of the invention as defined by the appended claims.