Abstract:
A wafer container includes a container body, the internal of which is disposed with a plurality of slots for supporting a plurality of wafers and an opening is formed on one sidewall of which for importing and exporting said plurality of wafers, and a door with an inner surface, which is joined with opening of the container body with the inner surface for protecting the plurality of wafers in the container body, the characteristic in that: at least one restraint module is disposed on the inner surface of the door, the restraint module including a base which is disposed with a plurality of restraints arranged at intervals and an opening, and a snap-fitting piece is disposed on the inner surface of the door for snap-fitting the restraint module by passing the snap-fitting piece through the opening of the base of restraint module and rotating the restraint to an angle.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present field of the invention is related to a wafer container, and more particularly, to a structure for fixing a wafer restraint module on the door of the wafer container. 
         [0003]    2. Description of the Prior Art 
         [0004]    The semiconductor wafers are transferred to different stations to apply the various processes in the required equipments. A sealed container is provided for automatic transfer to prevent the pollution from occurring during transferring process.  FIG. 1  shows the views of wafer container of the conventional prior art. The wafer container is a front opening unified pod (FOUP) which includes a container body  10  and a door  20 . The container body  10  is disposed with a plurality of slots  11  for horizontally placing a plurality of wafers, and an opening  12  is located on a sidewall of the container body  10  for importing and exporting. Further, the door  20  includes an outer surface  21  and an inner surface  22 , in which the door  20  is joined with the opening  12  of the container body  10  via inner surface  22  to protect the plurality of wafers within the container body  10 . Furthermore, at least one latch hole  23  is disposed on the outer surface  21  of the door  20  for opening or closing the wafer container. According to the aforementioned, due to that the wafer is placed in the container body  10  horizontally, thus, the FOUP needs a wafer restraint component to prevent the wafer from displacement or from movement toward the opening  12  of container body  10  occurring during the wafer transportation due to vibration. 
         [0005]      FIG. 2  is a view of a front opening unified pod (FOUP) as described in U.S. Pat. No. 6,736,268. As shown in  FIG. 2 , the inner surface  22  of the door  20  is disposed with a recess  24  and the recess  24  is extended from the top  221  of the inner surface  22  to the bottom  222 , and is located between two latch components  230  (inside of the door  20 ). Two wafer restraint modules  100  are further disposed in the recess  24 . The wafer restraint modules  100  include a plurality of wafer contact heads (not shown in Figure) to sustain corresponding wafers so as to prevent the wafer from displacement or movement toward the door opening due to vibration occurring in the wafer transportation procedure. However, the above-mentioned wafer restraint modules  100  are disposed in the recess  24  of the inner surface  22  of the door  20 , and the wafer is merely attached to the inner surface  22  of the door  20  or the wafer is partially settled down within the recess  24 , and thus the length between the front side and the back side of the FOUP can not be effectively shortened. 
         [0006]    Then, referring to  FIG. 3 , which is a sectional view of a wafer restraint component of prior art in the process of restricting the wafer. The wafer restraint component  110  is disposed in the opening  0  on the inner surface  22  beside the recess  24  of the door  20 , wherein a plurality of right-left symmetrical spring arms  120  of wafer restraint component  110  are used for respectively sustaining each wafer to prevent the wafer from displacement or movement toward the door opening due to vibration occurring in the wafer transportation procedure. However, in the aforementioned structure, a row of openings O need to be further disposed on two sides of the inner surface  22  of the door  20 , and a bolt  120 P and a round-shaped ring are to be further disposed on the wafer restraint component  110  for the wafer restraint component  110  to be insertingly disposed and thus fixed in the opening O. Such structure turns out to be complex in terms of manufacturing and assembling, and not only does the disposition of a plurality of openings O lead easily to poor air tightness but the plurality of openings O also easily become dead spots in the cleaning and drying process of the door  20 . 
       SUMMARY OF THE INVENTION 
       [0007]    In wafer container of the prior art, the design of its wafer restraint component or wafer restraint module makes it unachievable for the size of wafer container to be reduced, hard for dust particles to be cleaned up, and easy for wafers to come loose. One objective of the present invention is thus to provide a front opening unified pod (FOUP) with wafer restraint module, in which the wafer restraint module is disposed on the platforms on two sides of the recess of inner surface of the door for wafer to be fully and effectively filled in the recess to shorten the length between the front side and the back side of the FOUP. 
         [0008]    Another objective of the present invention is to provide a front opening unified pod (FOUP) with wafer restraint module, wherein the wafer restraint module can be easily and stably installed or fixed on the platforms on two sides of the recess so that the disposition of two rows of openings on the inner surface of the door that will cause difficulties in manufacturing and assembling process is not needed. 
         [0009]    Still another objective of the present invention is to provide a front opening unified pod (FOUP) with wafer restraint module, in which the wafer restraint module is disposed on the platforms on two sides of the recess of inner surface of the door; therefore, dust particles generated due to friction between wafer restraint component and wafer can be gathered in the corner of recess and can be easily cleaned up when cleaning the wafer container without needing to remove the wafer restraint module. 
         [0010]    According to above objectives, the present invention provides a front opening unified pod (FOUP), which includes a container body and a door. A plurality of slots are disposed in the container body for sustaining a plurality of wafers, and an opening is formed on one sidewall of the container body for importing and exporting the plurality of wafers. The door includes an outer surface and an inner surface; the door joins with the opening of container body via its inner surface for protecting the plurality of wafers in the container body. The characteristic of front opening unified pod (FOUP) in that: at least one restraint module is disposed on the inner surface of the door, the restraint module including a base which is disposed with a plurality of restraints arranged at intervals and an opening, and a snap-fitting piece is disposed on the inner surface of the door for snap-fitting the restraint module, wherein the snap-fitting piece snap-fits the base of wafer restraint module and fixes the wafer restraint module on the inner surface of the door by passing the snap-fitting piece through the opening of the base of wafer restraint module and rotating the wafer restraint module to an angle. 
         [0011]    Moreover, the base of the aforementioned restraint module further includes a plurality of subsidiary openings for being fixed to the snap pillar of the inner surface of the door via snapping on the snap pillar to achieve better fixing effect, allowing the restraint module to be stably and fixedly installed or fixed on the inner surface of the door. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]    The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated as the same becomes better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein: 
           [0013]      FIG. 1  is a view of a front opening unified pod (FOUP) of the prior art; 
           [0014]      FIG. 2  is a view of the door of a front opening unified pod (FOUP) of the prior art; 
           [0015]      FIG. 3  is a sectional view of a wafer restraint component of the prior art in the process of restricting the wafer; 
           [0016]      FIG. 4  is a view of a front opening unified pod (FOUP) of the present invention; 
           [0017]      FIG. 5  is a view of wafer restraint module of a front opening unified pod (FOUP) of the present invention in the process of contacting the wafer; 
           [0018]      FIG. 6A  and  FIG. 6B  are views of wafer restraint module of front opening unified pod (FOUP) of the present invention being not yet fixed to and already fixed to the inner surface of the door; 
           [0019]      FIG. 7  is a view of the arrangement of the plurality of restraint components of wafer restraint module of the present invention at intervals; 
           [0020]      FIG. 8A  to  FIG. 8C  are views of another design of opening of the base of wafer restraint module of the present invention; 
           [0021]      FIG. 9  is a view of another kind of arrangement of the plurality of restraint components of wafer restraint module of the present invention at intervals; 
           [0022]      FIG. 10  is a view of restraint components in another kind of arrangement of the present invention in the process of contacting the wafer; 
           [0023]      FIG. 11  is a view of another kind of front opening unified pod (FOUP) of the present invention; 
           [0024]      FIG. 12A  is a view of wafer restraint module of another kind of front opening unified pod (FOUP) of the present invention starting to contact the wafer; and 
           [0025]      FIG. 12B  is a view of wafer restraint module of another kind of front opening unified pod (FOUP) of the present invention completely contacting the wafer. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0026]    In order to disclose the skills applied in, the objectives of, and the effects achieved by the present invention in a more complete and clearer manner, preferred embodiments are herein described below in detail with related drawings disclosed for reference. 
         [0027]    First, referring to  FIG. 4 , which is a view of a front opening unified pod (FOUP) of the present invention. The front opening unified pod (FOUP) includes a container body  10  and a door  20 . A plurality of slots  11  are disposed in the container body  10  for sustaining a plurality of wafers, and an opening  12  is formed on one sidewall of the container body  10  for importing and exporting the plurality of wafers. The door  20  includes an outer surface  21  and an inner surface  22 , and in the central part of the inner surface  22  of the door  20  is disposed with a recess  24 . The recess  24  further divides the inner surface  22  of the door  20  into two platforms  25 , and a wafer restraint module  30  is further disposed on each of the two platforms  25 . 
         [0028]    And as shown in  FIG. 5 , when the door  20  closes the container body  10 , since no other components are disposed in the recess  24 , the recess  24  can be used for accommodating a plurality of wafers in the container body  10  to shorten the length between the front side and the back side of the FOUP. And the wafer restraint modules  30  on the platforms  25  can also push each wafer in the container body  10  to a fixed position and restrict it from shaking. Since the wafer restraint module  30  is not placed in the recess  24 , thus when the process of cleaning wafer container is performed, dust particles can be easily cleaned up with no need to remove the wafer restraint module  30 . Moreover, a latch component (not shown in Figure) is further disposed in each of the two platforms  25  of the present invention, and each latch component forms latch hole on corresponding outer surface  21  for facilitating the closing or opening of the door  20 . 
         [0029]    Referring to  FIG. 6A  and  FIG. 6B , which are views of wafer restraint module of the front opening unified pod (FOUP) in  FIG. 4  being not yet fixed to and already fixed to the inner surface of the door. The wafer restraint modules  30  of the present invention are located on the two platforms  25  on two sides of the recess  24 . The wafer restraint module  30  includes a base  31 , and the base  31  includes two longer sides  31 L and two shorter sides  31 S, near one of the longer sides  31 L are a plurality of restraint components  300  disposed at intervals. Moreover, the base  31  further includes an opening  32 , and the shape of opening  32  can be rectangular, rhomboid, or oval; a snap-fitting piece  26  with protruding portion  261  and snap-fitting portion  262  is disposed on the inner surface  22  of the door  20 , one end of protruding portion  261  being fixed on the inner surface  22  of the door  20  and the other end (or free end) being connected to the snap-fitting portion  262 , the shape or size of snap-fitting portion  262  being the same as those of opening  32  of base  31 , being able to be rectangular, rhomboid, or oval. Therefore, the snap-fitting piece  26  can pass through the opening  32  of the base  31  of wafer restraint module  30  and after the wafer restraint module  30  is rotated to an angle (for example, rotated 90 degrees clockwise in  FIG. 6A  and  FIG. 6B ), the snap-fitting piece  26  snap-fits the base  31  of wafer restraint module  30  and fixes the wafer restraint module  30  on the inner surface  22  of the door  20 . 
         [0030]    And as shown in  FIG. 6A , the base  31  of wafer restraint module  30  further includes a plurality of subsidiary openings  33 , and on the inner surface  22  of door  20  corresponding to the plurality of subsidiary openings  33  a plurality of snap pillars  27  are further included, the diameter of free end of snap pillars  27  being slightly longer than the diameter of subsidiary openings  33 . Therefore when the snap-fitting piece  26  snap-fits the base  31 , the subsidiary openings  33  can be further snapped on the lower rim of free end of snap pillars  27  for reinforcing the fixation of wafer restraint module  30  and its base  31  on the inner surface  22  of the door  20 . 
         [0031]    When the aforementioned snap-fitting piece  26  and snap pillars  27  on the inner surface  22  of the door  20  snap-fit the opening  32  and subsidiary opening  33  on the base  31 , as shown in  FIG. 6B , the plurality of restraint components  300  of wafer restraint module  30  on two sides of recess  24  arranged at intervals are in couple so that each corresponding restraint component  300  can contact a wafer to prevent wafer in the container body from moving toward the direction of the opening during transportation process. 
         [0032]    Referring to  FIG. 7 , which is a view of the arrangement of the plurality of restraint components of wafer restraint module of the present invention at intervals. As shown in  FIG. 5  and  FIG. 7 , the plurality of restraint components  300  of the wafer restraint module  30  arranged at intervals are a plurality of suspended arms  301  formed by the extension of one of the longer sides  31 L of the base  31  that is nearer to the recess  24 , a semicircle-like protruding portion  302  being formed between each suspended arm  301  and its free end, and the protruding portion  302  being disposed with a guide notch  32 G for contacting wafer in the container body. There is gap between neighboring restraint components  300  for the restraint components  300  to correspond to wafers in the container body  10 . And the surface of guide notch  32 G that contacts wafer can be coated with a wear-resisting material, such as polyetheretherketone (PEEK), to reduce friction and dust particles generated. Moreover, the width of guide notch  32 G can be equal to the thickness of wafer for the wafer to sink into the guide notch  32 G without moving up and down. Apparently, an angle is formed between the aforementioned base  31  and the suspended arm  301 , and the degree of angle can be 10˜60 degrees. 
         [0033]    Then, referring to  FIG. 8A  to  FIG. 8C , which are views of another design of opening of the base of wafer restraint module of the present invention. The base  31  of wafer restraint module  30  includes a rectangular mounting hole  34 , and in the rectangular mounting hole  34  are disposed with a plurality of elastic pieces  35  for an opening  32  to be formed among the elastic pieces  35 . And as shown in  FIG. 6A , a snap-fitting piece  26  is disposed on the inner surface  22  of the door  20 , and the structure of snap-fitting piece  26  includes protruding portion  261  and snap-fitting portion  262 . The shape and size of the aforementioned snap-fitting portion  262  and the opening  32  among elastic pieces  35  are the same, being in the shape of a rectangle. Therefore, the snap-fitting piece  26  can pass through the opening  32  of the base  31  of wafer restraint module  30  and after the wafer restraint module  30  is rotated to an angle, 90 degrees clockwise or 90 degrees counterclockwise for example, the snap-fitting piece  26  snap-presses the elastic pieces  35  and fixes the wafer restraint module  30  on the inner surface  22  of the door  20 . 
         [0034]    Then, referring to  FIG. 9  and  FIG. 10 , which are views of another kind of arrangement of the plurality of restraint components of wafer restraint module of the present invention at intervals. The plurality of restraint components  400  arranged at intervals are a plurality of supporting arms  401  formed by one longer side  31 L of the base  31  bending toward the recess  24 , and a sustaining portion  402  bending downward is formed on free end of each supporting arm  401  for contacting wafer in the container body. In one preferred embodiment of the present invention, the angle formed by the base  31  and the bend of supporting arm  401  is an acute angle, the degree of which can be determined according to the position of the wafer restraint module  30  disposed on the platform  25 ; for example, the angle can be 10˜60 degrees. Furthermore, in another preferred embodiment of the present invention, a quasi-V-shaped guide notch (not shown in Figure) is further formed on the sustaining portion  402  for allowing the wafer to be smoothly guided into the guide notch when being contacted by the sustaining portion  402  of restraint component  400  without moving up and down. In addition, in order to reduce friction for the wafer, the surface of guide notch that contacts wafer can be coated with a wear-resisting material, such as polyetheretherketone (PEEK). 
         [0035]    Then, referring to  FIG. 11 , which is a view of another front opening unified pod (FOUP) of the present invention, and  FIG. 12A  and  FIG. 12B , which are views of wafer restraint module of the front opening unified pod (FOUP) in  FIG. 11  starting to contact the wafer and completely contacting the wafer. The front opening unified pod (FOUP) includes a container body  10  and a door  20 , and the difference between this front opening unified pod (FOUP) and the front opening unified pod (FOUP) in  FIG. 4  is in that: the inner surface  22  of the door  20  does not include a recess. Therefore, the wafer restraint modules  30  are located on two sides of central part of inner surface  22 , wherein the wafer restraint module  30  includes a base  31  and on the base  31  is disposed with an opening  32  and a plurality of subsidiary openings  33  for the snap-fitting piece  26  and a plurality of snap pillars  27  on the inner surface  22  of the door  20  to fix the wafer restraint module  30  on the inner surface  22  of the door  20  (as shown in  FIG. 6A ). And each of the plurality of restraint components  500  on the wafer restraint module  30  includes a base portion  501  with one end fixed on the base  31  and the other end connected to a bent arm  502 , wherein the bent arm  502  includes a first contact end  503  and a second contact end  504 . 
         [0036]    The base portion  501  of each restraint component  500  as described above can be an elastic structure (for example: thermal-elastic plastic), and when the door  20  and the container body  10  are not yet or about to be joined with each other, the connecting line between first contact end  503  and second contact end  504  of restraint component  500  ( 503 - 504 ) is parallel to the inner surface  22  of the door  20 . Meanwhile, the wafer first contacts the first contact head  503 , and when the wafer contact the first contact head  503 , the base portion  501  deforms and levers the bent arm  502  for the other contact end of the bent arm  502 , i.e. second contact end  504 , to contact wafer sequentially. Meantime, as shown in  FIG. 12B , the door  20  is joined with the container body  10  and an included angle is formed between the connecting line between the first contact end  503  and the second contact end  504  of restraint component  500  ( 503 - 504 ) and the inner surface  22  of the door  20 . Apparently, each restraint component  500  contacts wafer with two contact ends, not only preventing the wafer from moving toward the center of the opening but also limiting the wafer to move toward two sides of the opening. Therefore, when the wafer restraint module  30  contacts wafer, a resultant forces pushing only toward center point of wafer can be generated without causing the wafer to shake from side to side. Moreover, the first contact end  503  and the second contact end  504  can each include a recess for the wafer to sink into the recess without moving up and down. 
         [0037]    Of course, the wafer restraint module  30  with a plurality of restraint components  500  can be used in the door  20  without recess  24 , and can also be used in the door  20  with recess  24 . And the aforementioned wafer restraint module  30  with a plurality of restraint components  300  and  400  can also be used in the door  20  without recess  24 . In addition, the structure of wafer restraint modules  30  used in the present invention can be an integrated structure to reduce the manufacturing cost. 
         [0038]    While the invention has been described by way of examples and in terms of the preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. To the contrary, it is intended to cover various modifications and similar arrangements as would be apparent to those skilled in the art. Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.