Abstract:
Methods and bracing systems for packaging circuit boards and other articles in accordance with the present invention dampen shocks and/or vibrations during shipping and storage, while avoiding the use of voluminous packaging materials commonly used for such tasks. A bracing system in accordance with one embodiment uses two load-bearing braces that can be connected with a circuit board and locked in place by a tray and lid. The brace system dampens shock and/or vibration, protecting sensitive, otherwise exposed components. This description is not intended to be a complete description of, or limit the scope of, the invention. Other features, aspects, and objects of the invention can be obtained from a review of the specification, the figures, and the claims.

Description:
TECHNICAL FIELD  
         [0001]    The present invention relates to packaging used for shipping shock and/or vibration sensitive articles.  
         BACKGROUND  
         [0002]    Circuit boards, hard disk drives, consumer electronics, and other shock and/or vibration sensitive articles require special packaging material when shipped inside cartons. Commonly, packaging material used to protect such sensitive articles includes expandable polyethylene, polystyrene Bubble Wrap®, polyurethane, styro-foam peanuts, preformed polystyrene foam or beads, preformed paperboard, etc. Ideally, the packaging material absorbs and dissipates shocks and vibrations impinging the shipping carton to minimize the shocks and vibrations experienced by sensitive articles.  
           [0003]    In order for commonly used packaging materials to minimize shock and vibration, large volumes of packaging material are used to envelop and cushion the sensitive article. Voluminous packaging material is expensive and takes up excessive space before and after use. Further, voluminous packaging material necessitates larger shipping cartons, compounding the cost of shipping. The shock/vibration dissipation performance of commonly used packaging materials can depend on how the user packages the sensitive article. If the commonly used packaging material provides inadequate protection, the only way to adjust dissipation performance is to add more packaging material, consequently increasing the shipping carton size.  
           [0004]    Alternatively, unitary packaging structures made of flexible polymeric materials allow shock and vibration to dissipate through flexing of the structure walls. U.S. Pat. Nos. 5,226,543, 5,385,232 and 5,515,976 disclose examples of unitary packaging structures. These unitary packaging structures dissipate shocks primarily in only one direction and can fail to provide adequate shock and vibration protection. U.S. Pat. No. 5,799,796 discloses an alternative unitary packaging structure for dissipating shock and vibrations that can provide improved shock and vibration protection and can be adjusted for more or less dampening.  
           [0005]    Many sensitive articles can vary widely in size and shape, making them difficult to package. For example, circuit boards can vary in layout, and in the number and size of components soldered, or connected with the board (and thus potentially protruding from the board).  
       
    
    
     BRIEF DESCRIPTION OF THE FIGURES  
       [0006]    Further details of embodiments of the present invention are explained with the help of the attached drawings in which:  
         [0007]    [0007]FIG. 1A is an partially exploded view of a bracing system in accordance with one embodiment of the present invention;  
         [0008]    [0008]FIG. 1B is a perspective view of the bracing system of FIG. 1A, showing braces having support surfaces positioned above an article;  
         [0009]    [0009]FIG. 2A is a plan view of a tray for the bracing system of FIG. 1 in accordance with one embodiment of the present invention;  
         [0010]    [0010]FIG. 2B is a side view of the tray of FIG. 1A;  
         [0011]    [0011]FIG. 3A is a plan view of a lid for the bracing system of FIG. 1 in accordance with one embodiment of the present invention;  
         [0012]    [0012]FIG. 3B is a side view of the lid of FIG. 2A;  
         [0013]    [0013]FIG. 4A is a perspective view of a brace for the bracing system of FIG. 1 in accordance with one embodiment of the present invention;  
         [0014]    [0014]FIG. 4B is a cross-section of the brace of FIG. 3A;  
         [0015]    [0015]FIG. 4C is a perspective view of the brace of FIG. 3A positioned to be connected with a circuit board;  
         [0016]    [0016]FIG. 4D is a cross-section of a brace in accordance with an alternative embodiment of the present invention;  
         [0017]    [0017]FIG. 4E is across-section of a brace in accordance with a second alternative embodiment of the present invention;  
         [0018]    [0018]FIG. 4F is a cross-section of a brace for packaging two circuit boards in accordance with another embodiment of the present invention; and  
         [0019]    [0019]FIG. 5 is a cross-section of the bracing system of FIG. 1. 
     
    
     DETAILED DESCRIPTION  
       [0020]    [0020]FIGS. 1A-5 illustrate one embodiment of a bracing system for packaging circuit boards in accordance with the present invention. As shown in FIG. 1A, the bracing system  100  comprises a tray  102  for supporting an article (a circuit board as shown), a first brace  106  and a second brace  108  removably connected with the article for supporting a vertical load, and a lid  104  connected with the tray  102 . The braces  106 ,  108  can be removably connected with opposite sides of the circuit board such that the braces  106 ,  108  have a longitudinal dimension perpendicular to a front bezel of the circuit board. As shown in FIG. 1B, when the circuit board lies flat within a recess of the tray  102  the braces  106 ,  108  extend vertically so that load bearing surfaces of the braces  106 ,  108  are positioned above electrical and mechanical components connected with the circuit board, allowing the braces  106 ,  108  to support a load applied to the lid  104 . A method for packaging circuit boards utilizing the bracing system  100  in accordance with one embodiment of the present invention can protect circuit boards or other articles from damage from shock and/or vibrations.  
         [0021]    [0021]FIG. 2A is a plan view and FIG. 2B is a side view of the tray  102  of FIG. 1 for supporting a circuit board in accordance with one embodiment of the present invention. The tray  102  can include a lip  222  along the periphery of the tray  102 , and a recessed base  224  within the tray  102 . The lip  222  can include male snaps  220  (shown in FIG. 2B protruding from the lip) and/or female snaps for mating with female and/or male snaps of the lid  104 . In other embodiments, the tray  102  does not include a lip  222 . In still other embodiments, the tray  102  and lid  104  are extruded or formed as a single piece having a hinge such that the tray  102  and lid  104  form a clamshell. One of ordinary skill in the art can appreciate the myriad of different configurations for connecting the tray  102  with the lid  104  such that an article can be contained between the tray  102  and lid  104 .  
         [0022]    As shown in FIG. 2A, the tray  102  can include a front portion having load-bearing corners  226  for supporting a bezel of the circuit board and one or more step structures  230  within the recessed base  224  abutting the bezel to prevent the circuit board from shifting forward in the tray  102 . The load-bearing corners  226  can be bulbous in shape so that the corners  226  can be partially crushed without contacting sharp corners of the front bezel, thereby avoiding piercing of the tray  102 . The recessed base  224  further includes at least one lateral step structure  232  on each side of the tray  102  for supporting the braces  106 ,  108  (and by extension the circuit board) such that the circuit board can be suspended over the recessed base  224  and a plurality of collapsible structures  228  for dampening shock and/or vibrations. FIG. 2A illustrates three such collapsible structures  228   a - c  formed along a transverse axis between the two sides of the tray  230 . The center transverse structure  228   b  is further recessed from the base  224  and can have perpendicular sidewalls, thus forming a narrow trench. If shock and/or vibration impacts the front or rear of the tray  102 , the center transverse structure  228   b  can absorb the shock and/or vibration by collapsing the narrow trench such that the sidewalls of the trench deform, and the gap created by the narrow trench closes slightly. Further, the other two transverse structures  228   a ,  228   c  can also be recessed from the base  224  and can further include a lateral bulge  236  so that the transverse structures  228   a ,  228   c  can absorb oblique shocks and/or vibrations. The collapsible structures  228  can have a variety of different geometries and can be designed to protect against impact from particular angles or sources. In other embodiments, the tray  104  can have additional or fewer collapsible structures  228 . In still other embodiments, the tray  104  need not have any collapsible structures  228 . One of ordinary skill in the art can appreciable the myriad of different configurations and arrangements with which the tray  104  can be formed.  
         [0023]    [0023]FIG. 3A is a plan view and FIG. 3B is a side view of the lid  104  in accordance with one embodiment of the present invention. The lid  104  can include a lip  340  along the periphery of the lid  104  and a raised top  348 . As described above, the lid lip  340  can include female snaps  342  and/or male snaps for mating with female and/or male snaps of the tray  102 . As with the tray  102 , the lid  104  need not include a lip  340 . The raised top  348  further includes at least one support structure  344  on each side of the tray  102  that contact the braces  106 ,  108  when the lid is connected with the tray  102 . The at least one support structure  344  can include a ledge  350  so that the at least one support structure  344  checks shifting of the braces  106 ,  108 , thereby preventing the braces  106 ,  108  from becoming dislodged from the circuit board. When a load is applied to the lid  104 , the load is transferred to the braces  106 ,  108 . Shocks and/or vibrations applied to the lid  104 , for example during shipping, can be absorbed by the braces  106 ,  108  which prevent contact with electrical and/or mechanical components connected with the circuit board.  
         [0024]    The raised top  348  of the lid  104  can further be shaped such that features of the top coincide with features of the tray  102 , thus multiple bracing systems  100  can be stacked on one another such that the bracing systems  100  resist moving relative to one another.  
         [0025]    The tray  102  and lid  104  can comprise high density polyethylene (HDPE), which provides resiliency for shock and vibration absorption. Alternatively, the tray  102  and lid  104  can comprise any thermoformable plastic. For example, the tray  102  and lid  104  can comprise low density polyethylene, acrylic, polystyrene, poly-carbonate, polymer grade ethylene and propylene (and other olefin polymers) etc, or a compound of two or more thermoformable plastics. The compound can further comprise non-plastic materials, such as glass for providing stiffness. In still other embodiment the tray  102  and/or lid  104  can comprise preformed paperboard or cardboard. One of ordinary skill in the art can appreciate the myriad of different materials that can be used to form the tray  102  and lid  104 .  
         [0026]    The tray  102  and lid  104  can be extruded from one or more sheets of material, or alternatively can be injection molded. The tray  102  and lid  104  can be formed such that the walls are thicker or thinner, as desired by the user. Different materials, and different wall thicknesses can result in different dampening performance. In some embodiments, it maybe desired that the tray  102  and lid  104  be comprised of different materials, or be comprised of similar materials having different thicknesses. One of ordinary skill in the art can appreciate the different configurations for the tray  102  and lid  104 .  
         [0027]    [0027]FIG. 4A is a perspective view of the brace  106 ,  108  of FIG. 1 for supporting a vertical load applied to the bracing system  100  in accordance with one embodiment of the present invention. Each brace  106 ,  108  can comprise a support surface  462  for distributing a vertical load, a clip  460  for connecting the brace  106 ,  108  with the circuit board, an upper compression member  464  for supporting a load applied to the support surface  462 , and a lower compression member  466 .  
         [0028]    [0028]FIG. 4B is a cross-section of the brace  106 ,  108  of FIG. 4A. The brace  106 ,  108  can have a vertical height such that when the clip  460  is connected with the circuit board, the support surface  462  is positioned above electrical components and mechanical components of the circuit board. The circuit board can include electrical components such as capacitors and microprocessors, or mechanical components such as cooling fans and heat sinks. These components can protrude significantly from the circuit board. The brace  106 ,  108  can be customized such that the brace  106 ,  108  has a vertical height sufficient to position the support surface  462  above these components.  
         [0029]    The upper compression member  464  can be connected between the support surface  462  and a vertical surface  470  of the brace  106 ,  108 . The load applied to the support surface  464  can create a bending moment at the junction of the support surface  462  and the vertical surface  470 . The width of the support surface  462  can be optimized so that the load provides a substantially compressive force to the compression member  464 . The compression member  464  resists the bending moment and redistributes the load. The support structure  462  can further include a brace ledge  468 . The brace ledge  468  contacts the lid ledge  350 , preventing the brace from shifting in place.  
         [0030]    The clasp  460  can comprise a slot having an opening that approximates the thickness of the circuit board or a metal backplate connected with the circuit board. As shown in FIG. 4C, the brace  106 ,  108  can be connected with the circuit board by sliding the lateral edge of the metal backplate of the circuit board into the slot of the clasp  460 . A second compression member  466  can be connected between the vertical surface  470  and the clasp  460 , and can resist a bending moment about the junction of the clasp  460  and the vertical surface  470 . In other embodiments, the clasp  460  can have a hinge so that the clasp  460  can be adjusted to accommodate different thicknesses of circuit boards and/or metal backplates. In still other embodiments, the clasp can have protuberances that snap into screw-mount holes of the circuit board and/or metal backplate, thereby preventing the circuit board from shifting. In still further embodiments, the clasp can be sized to hold a larger article, for example a flat-panel display, or fragile glass, etc. One of ordinary skill in the art can appreciate the different configurations of a clasp  460  for immobilizing the circuit board.  
         [0031]    [0031]FIG. 4D is a cross-section of an alternative embodiment of the brace  106 ,  108  in accordance with the present invention. The brace  106 ,  108  can have a second support structure below the clasp  460  having a second support surface  472 , a third compression member  480  connected between the clasp  460  and an extended vertical surface  478 , and a fourth compression member  476  connected between the extended vertical surface  478  and the second support surface  472 , such that the circuit board is suspended above the second support structure, thereby protecting components that can be connected with the opposite side of the circuit board. The second support structure can mirror the first support structure, or can have a different geometry. For example, the extended vertical surface  478  can have a smaller dimension than the first vertical surface  470 .  
         [0032]    In still other embodiments, the brace  106 ,  108  can have a rectangular cross-section. As shown in FIG. 4E, the brace can have two vertical surfaces  484 ,  486  for distributing the compressive forces resulting when a vertical load is applied to the support surface  482 . In other embodiments, the brace  106 ,  108  can have a circular, or elliptical cross-section. One of ordinary skill in the art can appreciate the myriad of different load-bearing configurations for the brace  106 ,  108 .  
         [0033]    Where it is desired that multiple circuit boards can be contained in a package, a brace  106 ,  108  can be used having multiple clasps. Once such brace  106 ,  108  is shown in FIG. 4E, and can include a structure similar to the brace  106 ,  108  shown in FIGS. 4A and 4D. The brace  106 ,  108  further includes a second clasp  461 , so that a second circuit board can be connected with each brace  106 ,  108  such that the metal backplate of the first circuit board opposes a metal backplate of the second circuit board. The brace  406 ,  408  can have bracket-type compression members, as shown in FIGS. 4A and 4D for distributing a load, or alternatively can have vertical compression members, as shown in FIG. 4E. Alternatively, the compression members can have a circular or elliptical cross-section, or some other geometry.  
         [0034]    The brace  106 ,  108  can comprise twenty-percent glass-filled poly-carbonate, which provides increased flex modulus, allowing the vertical surfaces  484  and support surfaces  462  of the brace  106 ,  108  to be made thinner. Alternatively, the brace  106 ,  108  can comprise a glass-filled poly-carbonate having a different percentage of glass. In other embodiments, the brace  106 ,  108  can comprise glass-filled acrylonitrile butadiene styrene (ABS). In still other embodiments, the brace  106 ,  108  can comprise any thermoformable plastic, for example polyethylene, acrylic, polystyrene, poly-carbonate, polymer grade ethylene and propylene (and other olefin polymers), etch, or a compound of two or more thermoformable plastics. The compound can further comprise non-plastic materials, such as glass for providing stiffness.  
         [0035]    The brace  106 ,  108  can be melt extruded in a single piece have a variable length, allowing the brace  106 ,  108  to be cut to a desired length, or alternatively the brace  106 ,  108  can be injection molded. The flexibility in manufacturing the brace  106 ,  108  can provide an advantage in that a single brace design can be utilized for circuit boards having a variety of different shapes and sizes.  
         [0036]    [0036]FIG. 5 is a partial cross-section of the bracing system of FIG. 1 showing the assembled bracing system without an article. As can be seen, the tray  102  is connected with the lid  104  by press-fitting male snaps  220  of the tray  102  into female snaps  342  of the lid  104 . The braces  106 ,  108  lock into place between the tray  102  and the lid  104 , with the brace ledge  468  contacting the lid ledge  350  such that the brace is immobilized and cannot pivot forward and collapse in response to a lateral shock and/or vibration. As can further be seen, when a load is applied, the brace is compressed and dampens at least the vertical loads applied to the bracing system, while the collapsible structures of the tray  102  and lid  104  can dampen at least the lateral loads applied to the bracing system.  
         [0037]    A method for packaging circuit boards in accordance with one embodiment of the present invention includes connecting a brace  106 ,  108  with a circuit board by sliding the slot of the clasp  460  onto an edge of a metal backplate connected with the circuit board such that the support surface of the braces  106 ,  108  are above components of the circuit board. The circuit board and braces  106 ,  108  are placed in the tray  102  such that corners of a front bezel of the circuit board rest on the corners  226  of the front portion of the tray  102 , braced by one or more step structures  230 , with the braces  106 ,  108  being supported by at least one lateral step structure  232 . The lid  104  can then be connected with the tray  102  such that an at least one support structure  344  locks the braces  106 ,  108  in place, by press-fitting the snaps of the tray  102  into the snaps of the lid  104 .  
         [0038]    The foregoing description of preferred embodiments of the present invention has been provided for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many modifications and variations will be apparent to one of ordinary skill in the relevant arts. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application, thereby enabling others skilled in the art to understand the invention for various embodiments and with various modifications that are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims and their equivalence.