Abstract:
A hinged mask-package container with a spring latch for use in the transportation and storage of substrates. The container has a base and lid secured by a slidable spring latch that accepts the container&#39;s lid by sliding along the rail when the lid is pressed down to meet the base and then secures the lid and base by sliding back into its original position. The container also employs a living hinge made by an overmolding process whereby the hinge is formed in a first mold and then the container lid and base are formed and joined to the hinge in a second mold.

Description:
RELATED APPLICATION  
       [0001]     The present application claims the benefit of U.S. Provisional Application No. 60/657,314 filed Feb. 27, 2005, which is incorporated herein in its entirety by reference. 
     
    
     FIELD OF THE INVENTION  
       [0002]     This invention relates to sealable hinged latchable containers for storing and transporting masks used in manufacturing integrated circuits.  
       BACKGROUND  
       [0003]     Semiconductor components, such as integrated circuits, are made using semiconductor wafers. To this end, relatively fragile masks (or reticles) are used to project and define dimensions and locations of the structures in the final product. These masks are generally in the form of a substantially planar substrate. During manufacture, small particles of foreign material may settle upon the masks or substrate, hence damaging the mask or the product being manufactured or otherwise interfering with the manufacturing process. These foreign particles are present in the environments in which masks are stored and transported. Because of the fragile nature of masks and the necessity to prevent adherence of foreign particles to the masks, containers are used. These containers serve the dual purpose of protecting the masks from damage and providing a dust-free microenvironment. Containers for masks have conventionally been manufactured from separate top cover or lid and a bottom or base. The portions are molded separately with each having a hinge portion integral on the back side thereof. The containers are then assembled utilizing a metal hinge pin to complete the hinge. A simple manually slidable C-shaped latch positioned on a rail on the front of the base piece is manually slid to capture a tab on the top cover when closed to secure the package shut. The hinge portions are conventionally formed of the same materials as the top cover and base and typically has plastic to plastic rubbing contact as well as plastic to metal rubbing contact which can cause abrading and particle generation. A latch that secures a lid to a base automatically and a hinge that could be incorporated with minimal assembly steps and without the plastic to plastic or plastic to metal rubbing contact and thus without the associated particle generation would be quite desirable.  
       SUMMARY OF THE INVENTION  
       [0004]     The invention addresses the needs of the industry in part by a providing a container for storing and transporting masks and a process for making the container by sequentially molding its components using overmolding techniques and a living hinge. The container includes a lid, a base, a hinge, and a latching mechanism. In one embodiment, the hinge is formed of a first material by injection molding. The hinge is placed in a mold to overmold the base and cover thereon. Thus the base and lid formed integrally—or connected mechanically by the overmolding—to the hinge by a second injection molding. The hinge has a living hinge portion that functions with no rubbing or abrading contact. The latching mechanism, which includes a sliding latch member configured as a C-shaped latch carriage and an integrally formed spring, slidably engages a rail on the front side of the base. The spring biases the latch member to an original normal position that is the “latch” position. The latch can be automatically actuated, that is, moved out of the latch position to accept and latch with the top cover, when a ramp-shaped extension, that is a cam surface, of the lid presses against a ramp-shaped beveled surface, a cooperating cam surface, of the latch as the lid is being closed to the base. The force of the downward moving lid extension contacts a cam surface and urges each of the two latch carriages outboard until the lid tab extensions enters notches in the latch carriages, thereby releasing the latch carriage to it original position under the force of the spring. When the lid extension is thus seated, it is aligned with the rail and the latch spring retains the latch mechanism in a locked and closed position. Another downwardly facing ramp-shaped beveled edge of the latch may be used to automatically open the latch mechanism by an actuator moving upwardly from below.  
         [0005]     A feature and advantage of the invention is that the latch mechanism may be manually or robotically operated and robotically operated with simple vertical moving actuating arms extending either upwardly from below or downwardly from above.  
         [0006]     A feature and advantage of the invention is a minimal number of parts. For example each latch mechanism consists of only one additional component in addition to the portions of the top cover and base that are utilized. This facilitates simplicity, easy cleaning, an minimizes manufacturing costs such as assembly costs.  
         [0007]     A feature and advantage is the lack of rubbing components in the hinge.  
         [0008]     A feature and advantage of preferred embodiments of the invention is that the latch carriages both are biased inwardly to their latched position facilitating robotic actuation for opening by inserting between the two latch carriages an actuator with cam surfaces that can simultaneously urge outwardly both latch carriages by a simple vertical motion coming either from above or below the container.  
         [0009]     A feature and advantage of preferred embodiments is that the latch carriages have cam surfaces that can be both actuated by a actuator cam portion on the top lid and also robotically. Moreover the latches are readily operated manually.  
         [0010]     These and other objects, features, and advantages of this invention will become apparent from the description which follows, when considered in view of the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]      FIG. 1  is a perspective view of one embodiment of a container according to the inventions herein when in a closed position;  
         [0012]      FIG. 2  is a perspective view of the inside of the container of  FIG. 1  when in an open position;  
         [0013]      FIG. 3  is a plan view of the outside of the container of  FIG. 1  when in an open position.  
         [0014]      FIG. 4  is a side, cross sectional view of the container of  FIG. 1  when in an open position.  
         [0015]      FIG. 5  is a perspective view illustrating the function of the latch mechanism with the container partially open and the latch carriage in its normal position.  
         [0016]      FIG. 6  is a perspective view illustrating the function of the latch mechanism with the top cover commencing to engage the base at the latching mechanism deflecting the latch carriage outwardly.  
         [0017]      FIG. 7  is a perspective view illustrating the function of the latch mechanism with the top cover closed on the base at the latch carriage of the latching mechanism returned to its normal position.  
         [0018]      FIG. 8  is an view of the hinge before incorporation in the container.  
         [0019]      FIG. 9  is a view of the hinge before incorporation in the container.  
         [0020]      FIG. 10  is perspective view of the top of the hinge before incorporation in the container.  
         [0021]      FIG. 11  is perspective view of the bottom of the hinge before incorporation in the container.  
         [0022]      FIG. 12  is an end view of the hinge in a fully extended position before incorporation in the container.  
         [0023]      FIG. 13  is an end view of the living hinge portion of the hinge.  
         [0024]      FIG. 14  is an end view of the hinge in a fully folded position before incorporation in the container.  
         [0025]      FIG. 15  is an end view of the hinge in a fully folded position before incorporation in the container.  
         [0026]      FIG. 16  is a cross sectional side view of the hinge mechanism integrally molded with the lid and base of this invention;  
         [0027]      FIG. 17  is a perspective view of the container from the back side illustrating the hinge in the fully folded position.  
         [0028]      FIG. 18  is a front elevational view of the latch carriage.  
         [0029]      FIG. 19  is a top plan view of the latch carriage.  
         [0030]      FIG. 20  is a rear side elevational view of the latch carriage.  
         [0031]      FIG. 21  is an end view of the latch carriage.  
         [0032]      FIG. 22  is a perspective view of a corner of the base illustrating the latch carrage retracted from its normal position.  
         [0033]      FIG. 23  is a perspective view of the mechanism engaging lid extension of the present latch mechanism.  
         [0034]      FIG. 24  is a side view of a rail of the base as part of the latch mechanism.  
         [0035]      FIG. 25  is an illustration as to how both latch mechanisms can be simultaneously operated by a simple cam actuator either from above or below the container. 
     
    
       [0036]     It is understood that the above-described figures are only illustrative of the present invention and are not contemplated to limit its scope.  
       DETAILED DESCRIPTION  
       [0037]      FIGS. 1-4  show an embodiment of the mask (reticle) container of the invention. The container is depicted generally at  100  and includes an upper member such as a cover or lid  102 , a lower member or base  104 , a hinge  106 , and a pair of latching mechanisms  108 .  
         [0038]     The lid  102 , in turn, has a shell  110  with a generally planar top  112 , opposed longitudinal sides  114  and  116  and opposed lateral sides  118  and  120 , thereby defining a lid cavity  121 . Disposed within the lid cavity  121  are opposed recess structure  122  and  124  and laterally opposed reticle restraints or cushions  126  and  128 . Exemplary cushions suitable for some embodiments of the invention are disclosed in U.S. Pat. No. 6,216,873, hereby incorporated by reference.  
         [0039]     The base  104  has a shell portion  129  having a generally planar bottom  130 , opposed longitudinal sides  132  and  134 , and generally opposed lateral sides  136  and  138 , thereby defining a base cavity  140 . Posts  142 ,  144 ,  146 , and  148  are attached to the bottom  130  proximate the four comers of the base cavity  140 . Laterally opposed recessed structure  150  and  152  are positioned at the lateral sides  136  and  138 , respectively. A rim  154  is defined at the periphery of the lid  102  and a ledge  156  is defined at a periphery of the base  104 . The rim  154  sealingly contacts the ledge  156  when the container is closed.  
         [0040]     In use, a mask is placed in the cavity  140  and is supported and confined by the posts  142 - 148 . When the lid  102  is closed, cushions  126  and  128  resiliently confine the mask vertically and laterally.  
         [0041]     Referring to  FIGS. 2, 3 ,  4 , and  8 - 17 , the hinge  106  unitarily (or otherwise integrally) has a first hinge member  170  and a second hinge member  172 , which are separated by a hinge portion  174  as shown in  FIGS. 6-16 . The hinge portion  174 , as described in more detail below, is an area of reduced thickness to enable the hinge to functionally and pivotally flex when attached to the lid and base and constitutes a “living hinge.” First hinge member  170  may be considered to include a planar portion  180  terminating in a lip  182 . A second hinge member  172  has respective first, second, and third planar portions  186 ,  188 , and  190  and a lip  192 . As can be seen the first, second, and third planar portions  186 ,  188 , and  190  angularly adjoin and the third planar portion  190  terminates at the lip  192 . As best shown in  FIG. 13 , the hinge portion  174  is defined by a generally arcuate groove  194  and a generally opposed notch  196 .  
         [0042]     Referring to  FIGS. 1, 2 ,  4 - 7 , and  18 - 24 , each latching mechanism  108  has a latch carriage  200 , a rail  202 , and a top cover projection or extension  204 . Latch carriage  200 , as best shown in includes a C shaped in the vertical cross-section) body  208  accommodating a spring  210 . The spring is preferably serpentine in shape and is compressible within the body. The latch carriage  200  has beveled (angled) generally converging, inboard lateral edges  214  and  216  that function as cam surfaces. The latch carriage  208  also has a generally curvilinear front member  218 , with a plurality of gripping extensions  220 , and a rear member  222 . The rear member  222  defines upper and lower notches  224  and  226  via respective extensions  228  and  230  and lip  232  and  234  extending inwardly from the extensions  226  and  228 .  
         [0043]     The rail  202 , as best shown in  FIGS. 5-7 ,  22 , and  24 , has a first extension  240  extending from the longitudinal side  132  of the base  104 . Respective second and third extensions  242  and  244  extend from the first extension  240  and are dimensioned to slidingly accommodate the notches  226  and  228  of the latch  200 . The rail  202  may also include a spring mount  246  outboard the structure formed by the first second and third extensions  240 ,  242 , and  244 .  
         [0044]     Extension  250  extends from the longitudinal side  114  of the lid  102  and presents a generally angled surface  252  as shown in  FIGS. 23 and 25 . A lip  254  extends from a main portion  256  of the extension  250 . When the container is fully closed the lip  254  generally aligns with the third extension  244  of the base latch assembly.  
         [0045]     Latch  200  is slidingly disposed on rail  202  such that the spring  210  abuts and biases the latch  200  away from the spring mount  246 . When the container is closed, the angled surface  252  of the lid extension  204  contacts the angled lateral edge  214  of the latch  200 , thereby forcing the latch  200  to slide away there from and compressing the spring  210  against the adjacent spring mount  246 . When the lid is completely closed, the spring  210  decompresses to allow the latch  200  to be displaced away from the spring mount  246  such that the notch  224  of the latch  200  is accommodated partially by the rail  254 . In this position, the latch  200  spans the extension  215  and the rail  202 , thereby securing the lid in a closed position. The beveled edge  216  is useful for automatically opening the latch from above or below, such as by automatic handling equipment  257  as shown in  FIG. 26 . The handling equipment forces the latch  200  open by exerting an upward force on the beveled edge  216 , thereby urging the latch outboard and allowing the lid and base rail portions to disengage. Similarly, referring to  FIGS. 5, 6 , and  7 , the beveled edge  252  or cam surface of the projection of the top lid automatically causes the latch carriage to retract as indicated by the arrow  251  in  FIG. 6  by engagement with the beveled surface  214  of the latch carriage. The projection then clears the beveled surface allowing the latch carriage to snap back to its normal position as indicated by the arrow  253  of  FIG. 7 .  
         [0046]     In one embodiment, the container is made by a process that includes sequential molding operations. In one exemplary process, the hinge is molded and allowed to cure. Then the hinge is removed from the first mold and placed in a second mold. The second mold is injected with a second polymer suitable for the lid and base members.  FIG. 16  shows how the hinge is embedded in the present lid and base and how the lips  182  and  192  anchor and secure the hinge—in addition to mechanical or chemical bonding between the polymers used to form the hinge, lid and base. The latch  200  is molded separately, with the latch carriage and spring formed integrally. The integral lid, base, and hinge are removed from the second mold after being allowed to cure. The latch is installed on the rail  202 . Finally, cushions are affixed to the lid  102 . Suitable sequential molding processes are disclosed in U.S. Pat. Nos. 6,428,729, 6,719,381, 6,402,552, and 6,077,124, and U.S. Patent Application 20030025244, each hereby incorporated by reference.  
         [0047]      FIG. 16  shows the conformation of the hinge when the container of this invention is fully opened.  FIG. 14  shows the hinge in a closed position and  FIG. 15  depicts the hinge generally mid-way between the open and closed positions. These figures illustrate how hinging is accomplished when the hinge flexes at portions having reduced thickness at the hinge portion  174 . In certain embodiments the flexible hinge material may be mechanically attached to the base and top cover in a separate operation, rather that during an overmolding operation. In some embodiments the living hinge may be formed with two materials: a flexible material for the living hinge and another material suitable for attachment to the base and top cover by means such as welding or by a second overmolding operation.  
         [0048]     Suitable materials used to form the hinge include polypropylene and polyurethane, optionally with an inherently dissipative polymer to dissipate static electricity. Suitable materials for the lid, base, and hinge include acrylonitrile butadiene-styrene (ABS), optionally with a static dissipative property, e.g., StatPro 435™ is such a material utilized in molding these types of products by Entegris, Inc. the owner of the this application. Other polymers may also be used, depending on the specific application intended for the container. Polymers suitable for these and other applications are disclosed in Handbook of Plastics, Elastomers, and Composites, Charles A. Harper, Editor-in-Chief, Third Edition, 1996, McGraw-Hill, hereby incorporated by reference.  
         [0049]     Although not illustrated in the figures, an elastomeric seal may be utilized with the container to seal between the top cover and base when the container is closed. In certain embodiments, the seal may be formed before the top cover and base are molded and may be inserted in the molds for said top cover and base to be joined by overmolding.  
         [0050]     Because numerous modifications of this invention may be made without departing from the spirit thereof, the scope of the invention is not to be limited to the embodiments illustrated and described. Rather, the scope of the invention is to be determined by the appended claims and their equivalents.