Abstract:
A plurality of connecting elements projects from a body&#39;s surface. A plurality of indents is defined in the body&#39;s surface. Each stem element includes first and second stalks projecting orthogonally from the surface. The first stub includes a pyramidical cap section and at least one generally planar wall. The second stalk is generally parallel to the first stub and spaced apart from the at least one wall, defining a gap therebetween. The second stalk includes a stem projecting from the surface. A lip section extends from a distal end of the stem and protrudes outwardly relative to the stem. An engagement section extends from the lip section. A free end of the engagement section defines a distal end of the second stalk. An outer surface of the engagement section defines a first gradient tapering from the lip section to the distal end of the second stalk.

Description:
FIELD OF INVENTION 
       [0001]    The present invention relates generally to interconnect systems, and more particularly, to high density interconnect systems. 
       BACKGROUND 
       [0002]    Fasteners, solders and adhesives have been used to attach components to primary hardware and structures to establish an electrical connection therebetween. For example, integrated circuit (IC) chips are typically soldered to motherboards. However, solders are subject to problems such as cracking which may cause a circuit board to malfunction or to fail. Furthermore, solders conventionally include lead, which may be undesirable in some applications. Adhesives used to connect a component to a primary hardware often require a long cure time. Further, adhesives often employ undesirable solvents for attachment. Moreover, once the component is attached to a structure using solder or adhesive, the component may not be repositioned without damaging the component and/or the structure. 
         [0003]    Other options include coating the surface of mechanical interconnects with an electrically conductive material. Several of the known mechanical interconnect systems include hook and loop fasteners available under the trademark Velcro® from Velcro USA, Inc., Manchester, N.H. and reclosable fasteners available under the trademark 3M™ Dual Lok™ from 3M, St. Paul, Minn. However, such mechanical fasteners suffer from disadvantages such as unpredictable contact area, which may prove detrimental to consistent high electrical conductivity, and insufficient locking strength. These fasteners are also subject to frictional locking which may deform the fasteners upon multiple engagement/disengagement cycles. Such fasteners provide rather limited holding force that rapidly decreases with repeated cycles of engagement and disengagement. Alternatives are, therefore, desirable. 
       SUMMARY 
       [0004]    According to an embodiment of the invention, an article of manufacture includes a plurality of regularly spaced connecting elements projecting from a surface of the article and a plurality of regularly spaced indents in the surface. Each of the plurality of indents is adjacent to a corresponding connecting element of the plurality of connecting elements. Each connecting element of the plurality of connecting elements includes a first stub and at least one second stalk projecting substantially orthogonally from the surface. The first stub includes at least one generally planar wall and a pyramidical cap section. The at least one second stalk is separated from the at least one generally planar wall defining a first gap therebetween. The at least one second stalk includes a stem projecting substantially orthogonally, at a proximal end thereof, from the surface. A lip section extends from a distal end of the stem and protrudes outwardly relative to the stem. An engagement section extends from the lip section. A free end of the engagement section defines a distal end of the at least one second stalk. An outer surface of the engagement section defines a first gradient tapering from the lip section to the distal end of the second stalk. Each of the plurality of indents is adapted to receive a pyramidical cap section of a corresponding connecting element projecting from another article. 
         [0005]    The wall thickness of the engagement section decreases continuously from a first wall thickness of the lip section to a second wall thickness of the distal end of the second stalk. The wall thickness of the lip section decreases continuously from the first wall thickness of the lip section to a third wall thickness at the distal end of the stem. 
         [0006]    According to another embodiment of the invention, a system includes a first interconnecting article having a first plurality of regularly spaced connecting elements projecting from a first surface thereof and a plurality of regularly spaced indents defined in the first surface and interspersed between the first plurality of connecting elements. The system further includes a second interconnecting article configured for connecting with the first interconnecting article and has a second plurality of regularly spaced connecting elements projecting from a second surface thereof and a second plurality of regularly spaced indents defined in the second surface and interspersed between the second plurality of connecting elements. Each connecting element of the first and second pluralities of connecting elements includes a first stub and at least one second stalk projecting substantially orthogonally from one of the first and second surfaces. The first stalk includes at least one generally planar wall and a pyramidical cap section. The at least one second stalk is separated from the at least one generally planar wall by a first gap. The second stalk includes a stem projecting generally orthogonally, at a proximal end thereof, from one of the first and second surfaces. A lip section having extends from a distal end of the stem and protrudes outwardly relative to the stem. An engagement section extends from the lip section. A free end of the engagement section defines a distal end of the at least one second stalk. An outer surface of the engagement section defines a first gradient tapering from the lip section to the distal end of the at least one second stalk. Each of the first and second pluralities of indents is adapted for receiving a pyramidical cap section of a corresponding connecting element of one of the first and second pluralities of connecting elements. 
         [0007]    When the second article is superposed on the first article such that the pyramidical cap sections of the second plurality of connecting elements are in general contact engagement with the pyramidical cap sections of the first plurality of connecting elements, a sub-set of connecting elements of the first plurality of connecting elements defines a second central gap and accommodates a connecting element of the second plurality of connecting elements therein, upon application of a first force greater than a first predetermined threshold on at least one of the first and second articles urging the at least one of the first and second articles toward the other of the first and second articles. 
         [0008]    Application of a second force greater than a second predetermined threshold on at least one of the first and second articles in a direction opposite of the first force causes the connecting element of the second plurality of connecting elements to be released from the sub-set of the first plurality of connecting elements. 
         [0009]    An electrical interconnect apparatus includes a substrate and a plurality of regularly spaced connecting elements projecting from the substrate. Each of the plurality of connecting elements includes a first stub projecting substantially orthogonally from the substrate and having at least one generally planar wall and a pyramidical cap section. At least one second stalk projects from the surface and is separated from the at least one generally planar wall defining a first gap. The at least one second stalk includes a stem projecting substantially orthogonally, at a proximal end thereof, from the substrate. A lip section having a first wall thickness extends from a distal end of the stem. The first wall thickness is greater than a second wall thickness of the stem at the distal end. An engagement section extends from the lip section. A free end of the engagement section having a third wall thickness defines a distal end of the at least one second stalk. The wall thickness of the engagement section decreases from the first wall thickness at the lip section to the third wall thickness at the distal end of the second stalk. 
         [0010]    According to an embodiment of the invention, a plurality of regularly spaced indents are interspersed between the first plurality of connecting elements. Each of the plurality of the indents is configured to receive and accommodate a pyramidical cap section of the first stub of a connecting element projecting from another electrical interconnect apparatus. in general contact engagement therewith. Each of the plurality of indents is adjacent to at least one stem element of the plurality of connecting elements. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    Understanding of the present invention will be facilitated by consideration of the following detailed description of the exemplary embodiments of the present invention taken in conjunction with the accompanying drawings, in which like numerals refer to like parts and in which: 
           [0012]      FIG. 1  is a perspective view of an interconnecting body with a plurality of stem elements and a plurality of indents, according to an embodiment of the invention; 
           [0013]      FIG. 2  is a partial perspective view of the interconnecting body of  FIG. 1 ; 
           [0014]      FIG. 3  is a partial side view of the interconnecting body of  FIG. 1 , according to an embodiment of the invention; 
           [0015]      FIG. 4  is a partial top view of the interconnecting body of  FIG. 1 , according to an embodiment of the invention; 
           [0016]      FIG. 5A  is a schematic side view of a second stalk of the stem element of  FIG. 1 , according to an embodiment of the invention; 
           [0017]      FIG. 5B  is a schematic side view of a second stalk of the stem element of  FIG. 1 , according to another embodiment of the invention; 
           [0018]      FIG. 6A  illustrates first and second interconnecting bodies during a stage of engagement, according to an embodiment of the invention; 
           [0019]      FIG. 6B  illustrates the first and second interconnecting bodies of  FIG. 5A  during a stage of engagement, according to an embodiment of the invention; 
           [0020]      FIG. 6C  illustrates the first and second interconnecting bodies of  FIG. 5A  during a state of engagement, according to an embodiment of the invention; 
           [0021]      FIG. 7  is a schematic top view of an interconnecting body with a plurality of stem elements and a plurality of indents arranged in a square pattern, according to an embodiment of the invention; 
           [0022]      FIG. 8A  is a schematic top view of an interconnecting body with a plurality of stem elements and a plurality of indents arranged in a triangle pattern, according to an embodiment of the invention; 
           [0023]      FIG. 8B  is a schematic top view of an interconnecting body with a plurality of stem elements and a plurality of indents arranged in a square pattern, according to another embodiment of the invention; 
           [0024]      FIG. 9  is a schematic cross-sectional view of two conventional solid stems interacting with one another; 
           [0025]      FIG. 10A  is a chart illustrating the correlation of the engagement force and different values of overlap between the two solid stems of  FIG. 9  for a constant value of the coefficient of friction between the two solid stems of  FIGS. 9 ; and 
           [0026]      FIG. 10B  is a chart illustrating the correlation of the engagement force and different values of coefficient of friction between the two solid stems of  FIG. 9  for a constant value of the extent of the overlap between the two solid stems of  FIG. 9 . 
       
    
    
     DETAILED DESCRIPTION 
       [0027]    It is to be understood that the figures and descriptions of the present invention have been simplified to illustrate elements that are relevant for a clear understanding of the present invention, while eliminating, for purposes of clarity, many other elements found in such reclosable fasteners and interconnecting surfaces. However, because such elements are well known in the art, and because they do not facilitate a better understanding of the present invention, a discussion of such elements is not provided herein. The disclosure herein is directed to all such variations and modifications known to those skilled in the art. 
         [0028]    Referring to  FIG. 1 , an interconnecting body  100  is illustrated, according to an embodiment of the invention. Body  100  includes a base  110 , a plurality of regularly spaced connecting elements or stem elements  120 , of like dimensions, and a plurality of regularly spaced indents  130 , also of like dimensions, in base  110 . Each of the plurality of connecting elements or stem elements  120  projects generally orthogonally from a first surface  115  of base  110 . Each of the plurality of indents  130  is defined, adjacent to a corresponding connecting element  120 , in first surface  115  of base  110 . A second surface  117  of base  110  may be configured to be affixed or otherwise fastened to a component or a structure. In the illustrated embodiment, base  110  is a generally flat, planar substrate. In other embodiments, base  110  may take the form of a substrate having a curved profile. In yet other configurations, base  110  may take the form of an outer skin of one or more mechanical structures or electrical components such as circuit boards. 
         [0029]    In an exemplary embodiment, body  100  may be fabricated from engineering plastics using, for example, high tolerance injection molding processes, such as those currently in use for compact disc (CD) and Digital Video Disc (DVD) manufacture. Non-limiting examples of engineering plastics suitable for fabrication of body  100  include polycarbonates (PC), acrylonitrile butadiene styrene (ABS), polyamides (PA), polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polyphenylene oxide (PPO), polysulpone (PSU), polyetherketone (PEK), polyetheretherketone (PEEK), polyimides and polyphenylene sulphide (PPS). Other suitable materials include materials having high heat resistance, mechanical strength, rigidity, chemical stability and flame retardancy. In an exemplary embodiment, body  100  including stem elements  120  may be fabricated from an electrically conductive material. In an exemplary embodiment, a non-conductive plastic body  100  may be surface coated with a nano-composite material such as a carbon nanotube composite or with metallic nano-spheres for imparting and electrical conductivity to the embodiment. Since such coatings are known in the art, they are not described in detail for sake of brevity. In another embodiment, stem elements may be fabricated from an electrically conductive composite. Examples of electrically conductive composite include, but are not limited to, plastics that contain additives that impart such conductivity via inclusion of metallic powders, carbon black, carbon fibers, mats, and metalized glass fibers and spheres. 
         [0030]    In another configuration, body  100  including stem elements  120  may be fabricated from a thermally conductive material, for example, from carbon nanotube based composites. In another embodiment, the surface of body  100  or at least stem elements  120  may be coated with a thermally conductive material such as a carbon nanotube composite or with metallic spheres. In an exemplary embodiment, at least first stalk or stub  140  of a stem element  120  may be fabricated from an optically conductive material. 
         [0031]    Referring now to  FIGS. 2-4 , stem element  120  includes a first stalk or stub  140  and at least one second stalk  150 , both projecting generally orthogonally from surface  115 . In an exemplary embodiment, first stalk or stub  140  is a solid stalk. In another embodiment, first stalk  140  may be a hollow stalk. In the illustrated embodiment, first stalk  140  has a generally square cross-section having a width  145  (of  FIG. 3 ) and has four generally planar faces or walls  142 . In another embodiment, first stalk  140  may have a triangular cross-section having three generally planar faces or walls  142 . In yet other embodiment, first stalk  140  may have a cross-section shape and configured as a polygon. First stalk  140  is coalesced, at an end  144 , to, and extends from, surface  115  of base  110 . First stalk  140  further includes a pyramidical cap section  170 . Pyramidical cap section  170  is coalesced to, and extends from, a base  160  at a second end  146  of first stalk  140 . In the illustrated embodiment, wherein first stalk  140  has a square cross-section, pyramidical cap section  170  has a square base  160 . In another configuration, wherein first stalk  140  has a triangular cross-section, pyramidical cap section  170  has a triangular base  160 . First stalk  140  has a first height  148  between ends  144 ,  146 . Pyramidical cap section  170  has a height  172 . First stalk  140  has a second height  147  between an apex  171  of pyramidical cap section  170  and end  144 . In the illustrated embodiment, first stalk  140  is a unitary, monolithic structure coalesced to and extending from base  110 . 
         [0032]    In one configuration, second stalk  150  is a relatively slender stalk and is generally parallel with a generally planar face  142  of first stalk  140 . Second stalk  150  is spaced apart from face  142  of first stalk  140 , defining a gap  155 . In the illustrated embodiment, where first stalk  140  has four generally planar faces  142 , stem element  120  has four stalks  150 , each of which is generally parallel to a corresponding face  142 . Second stalk  150  is coalesced, at an end  152 , to and extends from surface  115  of base  110 . In an exemplary embodiment, second stalk  150  has a generally uniform wall thickness  151  between ends  152 ,  154 . In other embodiments, second stalk  150  may have a non-uniform wall thickness  151 , depending on the requirements of a given application. Second stalk  150  has a width  157 . In one configuration, width  157  of second stalk  150  is generally equal to width  145  of first stalk  140 . In other configurations, width  157  of second stalk  150  may be less than width  145  of first stalk  140 . In the illustrated embodiment, second stalk  150  is a unitary, monolithic structure coalesced to and extending from base  110 . 
         [0033]    Referring now to  FIG. 5A , second stalk  150  is schematically illustrated, according to an embodiment of the invention. Second stalk  150  includes a stem  260 , a lip section  250 , a disengagement section or locking section  220  and an engagement section  210 , according to an embodiment of the invention. Stem  260  is coalesced to and extends from surface  115  and has a wall thickness  151 . Stem  260  has a first end  152  and a second end  154  and has a height  149  which is the distance between ends  152 ,  154 . At a first end  222 , lip section  250  is coalesced to, and extends from, end  154  of stem  260 . Disengagement section  220  is defined between lip section  250  and stem  260  and extends from first end  222  to a second end  224 . At a first end  212 , engagement section  210  is coalesced to and extends from lip section  250 , corresponding to second end  224  of disengagement section  220 . Engagement section  210 , thus, extends between first  212  and second end  214 . Second stalk  150  has a height  218  which is the distance between ends  152  and  214 . 
         [0034]    Cap section  170  acts as an alignment mechanism for guiding a corresponding cap section (not shown) of a stem element (not shown) projecting from a second body (not shown) superposed on body  100  toward a central gap (not shown) defined by adjacent stem elements  120 . Engagement section  210  is configured to engage a corresponding engagement section (not shown) of the stem element (not shown) projecting from the second body superposed on body  100  and, responsive to an engagement therebetween, provides a bending force urging second stalk  150  in a radial direction toward first stalk  140 . Engagement section  210 , thus, serves to bend second stalk  150  inwardly  160 , to facilitate the entry of the stem element (not shown) into the gap (not shown) defined by adjacent stem elements  120  by widening the central gap (not shown). Engagement section  210 , by providing the bending forces, also reduces the kinematic friction between the engaging stem elements. Disengagement section  220  serves to engage a corresponding disengagement section  220  of the stem element (not shown) extending from the second body (not shown) superposed on body  100  and provide a holding force resisting the movement of the stem element (not shown) of the second interconnecting body (not shown) out of the gap defined by adjacent open stems  120 , when the interconnecting bodies are subject to a disengaging force pulling at least one of them away from the other body. 
         [0035]    Engagement section  210  has an inclined outer surface for engaging a corresponding engagement section (not shown) of the stem element (not shown) projecting from the second body (not shown) superposed on body  100  (of  FIG. 1 ). In an exemplary embodiment, engagement section  210  has a tapered cross-section having a first maximum wall thickness  230  at first end  212  and a second minimum wall thickness  240  at second end  214 . The wall thickness of engagement section  210 , thus, varies in a non-linear, continuously increasing fashion from second wall thickness  240  at second end  214  to first wall thickness  230  at first end  212 . Thus, engagement section  210  has a first gradient defined from second end  214  to first end  212 . The first gradient of engagement section  210  may be derived as the difference, between first wall thickness  230  and second wall thickness  240 , divided by a length  216  of engagement section  210 . In another embodiment illustrated in  FIG. 5B , first gradient of engagement section  210  may be determined as a function of linear distances from generally planar face  142 . For instance, the linear distance of a point on the outer surface of engagement section  210  at end  214  is designated by reference numeral  215  and the linear distance of a point on the outer surface of lip section  250  at end  212  is designated by reference numeral  217 . The first gradient may be determined by dividing the difference between the linear distances  215 ,  217  by length  216  of engagement section  210 . 
         [0036]    At a second end  224 , disengagement section or locking section  220  is coalesced to and extends from first end  212  of engagement section  210  and,. at a first end  222 , coalesces into end  144  of stem  260 . Disengagement section  220  has an inclined outer surface for engaging a corresponding disengagement section (not shown) of a stem element (not shown) projecting from the second body (not shown) superposed on body  100  (of  FIG. 1 ), when the stem element (not shown) is lodged in the central gap (not shown) defined by adjacent stem elements  120 . In an exemplary configuration, disengagement section  220  has a tapered cross-section having a first maximum wall thickness  230  at second end  224  and a second minimum wall thickness  151  at first end  222 . The thickness of disengagement section  220 , thus, varies in a non-linear, continuously decreasing fashion from first wall thickness  230  at lip section  250  to second wall thickness  151  at first end  222 . Thus, disengagement section  220  has a second gradient defined from first end  222  to second end  224 . The second gradient of disengagement section  220  may be derived as the difference, between first wall thickness  230  and second wall thickness  147 , divided by a length  226  of disengagement section  220 . In an exemplary embodiment, the second gradient of disengagement section  220  is greater than the first gradient of engagement section  210 . In another embodiment illustrated in  FIG. 5B , second gradient of disengagement section  220  may be determined as a function of linear distances from generally planar face  142 . For instance, the linear distance of a point on the outer surface of lip section  250  at end  224  is designated by reference numeral  217  and the linear distance of a point on the outer surface of stem  260  at distal end  154  is designated by reference numeral  225 . The second gradient may be determined by dividing the difference between the linear distances  217 ,  225  by length  226  of disengagement section  220 . 
         [0037]    Cap section  170  has a height  172  from base  160  to an apex  171 . In an exemplary embodiment, a height  148  of first stalk is greater than a height  218  of second stalk  150 . 
         [0038]    Referring again to  FIGS. 2-4 , plurality of indents  130  are illustrated in first surface  115  of base  110 , according to an embodiment of the invention. Each second stalk  150  of stem element  120  has one adjacent indent  130  in first surface  115 . In the illustrated embodiment, first stalk  140  has a square cross-section and, therefore, indent  130  has a corresponding square opening  136  in first surface  115 . Indent  130  has a profile complementary to cap section  170  and is, therefore, adapted to receive and accommodate therein a cap section  170  of first stub  140  projecting from another surface or substrate (not shown). Indent  130  has a depth  132 . Depth  132  of indent  130  is generally equal to height  172  of pyramidical cap section  170  and width  134  of indent  130  is generally equal to width  145  of first stalk  140 . In the illustrated embodiment, each indent  130  is surrounded by four stem elements  120 . In another configuration, first stalk  140  may have a triangular cross-section, in which case, indent  130  has a corresponding triangular opening in first surface  115 . Furthermore, in the triangular configuration, each indent  130  may be surrounded by three stem elements  120 . 
         [0039]    The following exemplary dimensions for stem elements  120  are for the illustrated embodiment wherein first stalk  140  has a square cross-section. In an exemplary embodiment, first stalk  140  having may have width  145  of about 150 microns (μm) and height  148  of about 120 μm, by way of non-limiting examples only. Cap section  170  may have a height  172  about 45 μm. In one configuration, stem  260  of second stalk  150  may have a width  157  of about 150 μm and wall thickness  151  of about 8 μm. Engagement section  210  may have height  216  of about 45 μm, second wall thickness  240  ranging from about 1 μm to about 5 μm and first wall thickness  230  of about 16 μm in an exemplary configuration. Disengagement section  220  may have length  226  of about 10 μm, first wall thickness  151  of about 8 μm and second wall thickness  230  of about 16 μm, in an exemplary embodiment. Gap  155  may be of about 20 μm, which may be generally equal to wall thickness  151  of stem  260 , in an exemplary configuration. 
         [0040]    In an exemplary embodiment, engagement section  210  may have a first gradient of about 0.8 and disengagement section  220  may have a second gradient of about 1.2. In one configuration, the ratio of the second gradient of disengagement section  220  to the first gradient of engagement section  210  may range from about 1.5 to about 3. The ratio of width  145  of first stalk  140  to wall thickness  151  of second stalk  150  may range from about 15 to about 25. The ratio of width  145  of first stalk  140  to gap  155  may range from about 5 to about 10. The ratio of wall thickness  151  of second stalk  150  to height  218  of second stalk  150  may range from about 8 to about 12. The ratio of width  157  of second stalk  150  to wall thickness  151  of second stalk  150  may range from about 15 to about 25. The ratio of width  145  of first stalk  140  to width  157  of second stalk  150  may range from about 0.9 to about 1.1. Indent  130  may have depth  132  of about 20 μm and a width  134  of about 150 μm. It will be understood that different dimensions and ratios may be selected for first stalk  140  and second stalk  150 , depending on the requirements of a given application and that the exemplary values provided above are non-limiting in nature. One skilled in the art will further appreciate that the given dimensions may be scaled down to nanometer levels by a factor of about 1000 as well as scaled up to millimeter levels by a factor of about 1000 without departing from the scope of the invention. 
         [0041]    Referring now to  FIGS. 6A-6C , a system  600  including first and second interconnecting bodies  310 ,  410  is illustrated, according to an embodiment of the invention. Each of first and second interconnecting bodies  310 ,  410  has a corresponding first and second plurality of regularly spaced stem elements or connecting elements  320 ,  420 , of like dimensions, projecting generally orthogonally from respective first and second surfaces  315 ,  415 . A corresponding first and second pluralities of regularly spaced indents  330 ,  430 , also of like dimensions, are defined in respective first and second surfaces  315 ,  415 . Each of the first and second pluralities of stem elements  320 ,  420  is spaced apart from adjacent stem elements by a predetermined distance D 1 . Likewise, each of first and second pluralities of indents  330 ,  430  are spaced apart by predetermined distance D 2 . In an exemplary embodiment, distances D 1 , D 2  may be equal to each other. Adjacent second stalks  150   a ,  150   b  of respective adjacent stem elements  420   a ,  420   b  are separated by a maximum distance  430  about their respective lip sections  250  (of  FIG. 5 ) and by a minimum distance  460  about their stems  260  (of  FIG. 2 ). Opposing second stalks  150   c ,  150   c  of stem element  320   a  are separated by a distance  450  about their respective lip sections  250 . Maximum distance  430  between two adjacent second stalks  150   a ,  150   b  of respective adjacent stem elements  420   a ,  420   b  is smaller than distance  450  between opposing second stalks  150   c ,  150   c  about their respective lip sections  250 , whereas minimum distance  460  between two adjacent stems  260  (of  FIG. 2 ) of respective adjacent stem elements  420   a ,  420   b  is greater than distance  450  between opposing second stalks  150   c ,  150   c  about their respective lip sections  250 . 
         [0042]    In the illustrated embodiment, a sub-set  420   a ,  420   b  of plurality of stem elements  420  of body  410  define a central gap  425  therebetween to receive and accommodate one stem element  320   a  projecting from body  310 . Likewise, a sub-set (not shown) of plurality of stem elements  320  of body  310  define a central gap (not shown) therebetween to receive and accommodate at least one stem element  420   a  projecting from body  410 . 
         [0043]    First and second bodies  310 ,  410  are positioned such that cap sections  170  of first plurality of connecting elements  320  are in general contact engagement with cap sections  170  of second plurality of connecting elements  420 . Upon application of an engagement force F on at least one of first and second bodies  410 ,  310 , at least one of second plurality of stem elements  320   a  is received and accommodated by central gap  425  defined by sub-set  420   a    420   b  of first plurality of stem elements  420  and at least one of first plurality of stem elements  420  is received and accommodated by the central gap (not shown) defined by a sub-set (not shown) of second plurality of stem elements  320 . Bodies  410 ,  310  are interconnected with each other via first and second pluralities of stem elements  420 ,  320 , as described in detail below. 
         [0044]    When first body  310  is superposed over second body  410 , pyramidical cap section  370  of stem element  320   a  and pyramidical cap section  470  of stem element  420   a  contact each other in a first stage of engagement. Pyramidical cap sections  370 ,  470  by virtue of their pyramidical shapes act as alignment mechanisms and guide stem elements  420   a ,  320   a  towards respective central gaps  425 ,  325 . As a result, pyramidical cap sections  370 ,  470  enter the respective central gaps  425 ,  325 , wherein respective engagement sections  210  of stem elements  420   a ,  320   a  engage each other. As set forth above, the distance between lip sections  250  of adjacent second stalks  420   a ,  420   b  is smaller than the distance  450  between opposing second stalks  150   g . Consequently, stem elements  420   a ,  320   a  encounter resistance to further progress of stem elements  420   a ,  320   a  into respective central gaps  325 ,  425 . However, a continuous application of engagement force F and the tapered complementary profiles of engagement sections  210  cause bending forces to be applied on stems  260  (of  FIG. 2 ) of stem elements  420   a ,  320   a . When engagement force F exceeds a first predetermined threshold, the bending forces are sufficient to permit the entry of stem element  420   a ,  320   a  into respective central gaps  325 ,  425 . 
         [0045]    Given the relatively slender thickness  151  of stem  260  (of  FIG. 5 ) compared to height  218  (of  FIG. 5 ), engagement force F causes adjacent second stalks  150  of stem element  420   c ,  420   d  to be pushed inward toward their respective first stalks  140  as shown by arrows A-A. Simultaneously, opposing second stalks  150  of stem element  320   c  are pushed inward toward first stalk  140  as shown by arrows B-B. Thus, maximum distance  430  between adjacent second stalks  150  of stem elements  420   c ,  420   d  increases sufficiently to permit the entry of stem element  320 , into central gap  425 . Finally, as the application of engagement force F is continued, pyramidical cap section  470  is received and accommodated by an indent (not shown) in surface  315  and pyramidical cap section  370  is received and accommodated by, as illustrated in  FIG. 6C . At this stage, disengagement sections  220  of stem elements  320 ,  420  engage each other and lock stem elements  320 ,  420  in respective central gaps  425 ,  325 . First and second bodies  410 ,  310  are thus interconnected. 
         [0046]    Because the second gradient of disengagement section  220  is relatively greater than the first gradient of engagement section  210 , a disengagement force required to pull stem element  420   a  out of central gap  325  in a direction opposite to that of the engagement force is greater than the engagement force required to insert stem element  420   a  into central gap  325 . 
         [0047]    Referring now to  FIG. 7 , stem elements  120  are arranged in a square pattern as described below, in an embodiment of the invention. Any four adjacent second stalks  150   a ,  150   b ,  150   c ,  150   d  of the plurality of stem elements of  120 , for instance, stem elements  120   a ,  120   b ,  120   c ,  120   d , which define a central gap  425  for receiving and accommodating stem element  320   a  and surround an indent  130 , define the vertices of a square. Thus, in a square pattern, each stem element  120   a  of body  100  engages four stem elements (not shown) of a superposed corresponding interconnecting surface (not shown). A width  710  of second stalk  150   a  is equal to a width  710  of second stalk  150   b , to a width  710  of second stalk  150   c  and to a width  710  of second stalk  150   d . 
         [0048]    Now referring to  FIG. 8A , stem elements  620   a ,  620   b ,  620   c  of interconnecting body  610  are arranged in a triangle pattern as described below, according to another embodiment of the invention. Any three adjacent second stalks  650   a ,  650   b ,  650   c  of stem elements  620   a ,  620   b ,  620   c , which define a central gap  625  for receiving and accommodating a stem element (not shown) projecting from another body (not shown), and surround an indent  630 , define the vertices of an equilateral triangle. Central gap  625  receives and accommodates a stem element (not shown) of a superposed interconnecting body (not shown). Thus, in a triangle pattern, each stem element (not shown) of a body (not shown) engages three stem elements  620   a ,  620   b ,  620   c  of body  610 . Width  710  of first stalk  650   a  is equal to width  710  of second stalk  650   b  and to width  710  of third stalk  650   c . 
         [0049]    Referring now to  FIG. 8B , another embodiment of an interconnecting body  800  is illustrated. Stem elements  820  and indents  830  are arranged in a generally linear fashion on an outer surface of body  800 . In the illustrated embodiment, each stem element  820  has first and second opposing second stalks  840 . Any two adjacent stem elements  820  define a central gap therebetween to receive a stem element (not shown) projecting from a body (not shown) superposed on body  800 . 
         [0050]    In other embodiments, stem elements  120  may be arranged in different patterns, such as pentagon, hexagon and other geometrical patterns, depending on the requirements of a given application. It will be appreciated that square and triangle patterns of stem elements result in a tight pattern, having higher density, as compared to other polygonal patterns. 
         [0051]    Referring now to  FIG. 9 , two conventional solid stems  810 ,  830  in prior art reclosable fastener surfaces are schematically illustrated. Stem  810  has a mushroom head  820  and stem  830  has a mushroom head  840 . For a given radius R of mushroom heads  820 ,  840  and a given distance  850  between stems  810 ,  830 , an overlap  860  is given by: 
         [0000]      Overlap=2 R −Distance between two stems.
 
         [0052]      FIGS. 10A ,  10 B illustrate the correlation between the engagement force, the extent of overlap of two mushroom heads and the coefficient of friction between the two mushroom heads.  FIG. 10A  illustrates the increase in engagement forces as the extent of overlap increases for a constant coefficient of friction 0.1.  FIG. 10A  further illustrates that for a coefficient of friction of 0.1, engagement is not possible when overlap is 0.06 times radius R of mushroom head  820 ,  840  due to friction locking between mushroom heads  820 ,  840 . For instance, curve  870  illustrates the engagement force for an overlap of 0.05 times radius R and curve  880  illustrates the engagement force for an overlap of 0.06 times radius R. Likewise,  FIG. 10B  illustrates the increase in the engagement forces as the coefficient of friction increases for a constant overlap of 0.05 times radius R of mushroom heads  820 ,  840 .  FIG. 10B  further illustrates that for a constant overlap of 0.05 times radius R, engagement is not possible when coefficient of friction exceeds 0.2 due to frictional locking between mushroom heads  820 ,  840 . For example, curve  875  represents the engagement force for coefficient of friction of 0.1 whereas curve  885  represents the engagement force for coefficient of friction of 0.2. Thus, for conventional solid stems, friction locking may occur when any of the extent of overlap and the coefficient of friction of the stem material increases beyond a threshold. 
         [0053]    An advantage of multiple stems connecting elements with two stalks is that the engagement and disengagement forces are independent of surface coefficient of friction between the stem elements. Therefore, interconnecting bodies with multiple stems connecting elements are not subject to friction locking encountered in the known prior art interconnecting systems with solid stems under certain circumstances. Another advantage of the multiple stems connecting elements is that during engagement, entire second stalk is subjected to deformation. Such deformation of the entire second stalk keeps maximum strains in the second stalk within the material elastic limits. Yet another advantage of the multiple stems connecting elements with first and second stalks is that the engagement and disengagement forces may be controlled by changing the first and second gradients, respectively, of the engagement and disengagement sections. 
         [0054]    Another advantage of the multiple stem connecting elements with first stalk is that the pyramidical cap section of the first stalk provides self-aligning mechanism for the plurality of stem elements. Yet further advantage of the pyramidical cap section is that when first and second interconnecting surfaces are superposed and engaged with each other, the pyramidical cap sections are received and accommodated in the indents with opposing surfaces, providing a large contact surface area. Such contact between the stem elements and the opposing surfaces results in achieving enhanced electrical and thermal conductivities between the interconnecting bodies. The disclosed multiple stems connecting elements separate the functionalities of the first stub and second stalk: the second stalk predominantly serves to provide mechanical locking between the two interconnecting surfaces, whereas the first stalk or stub may serve as alignment mechanism as well as to provide one or more of thermal and electrical conductivities between the two interconnecting surfaces. Yet another advantage of the disclosed multiple stems connecting elements is that two articles or substrates with such connecting elements may be engaged and disengaged multiple times without significant loss of tensile and shear holding forces. 
         [0055]    According to an embodiment of the invention, first stalk of the stem element may be used for optical conductivity. Optical conductivity may be achieved by embedding graded index lenses, fiber optic waveguides, geometrically shaped lenses, axicons, and hollow-core waveguides into the first stalk. As such, the interconnect system may be utilized for electrical, optical, and a combination of electrical and optical connections therebetween. 
         [0056]    While the foregoing invention has been described with reference to the above-described embodiment, various modifications and changes can be made without departing from the spirit of the invention. Accordingly, all such modifications and changes are considered to be within the scope of the appended claims. Accordingly, the specification and the drawings are to be regarded in an illustrative rather than a restrictive sense. The accompanying drawings that form a part hereof, show by way of illustration, and not of limitation, specific embodiments in which the subject matter may be practiced. The embodiments illustrated are described in sufficient detail to enable those skilled in the art to practice the teachings disclosed herein. Other embodiments may be utilized and derived therefrom, such that structural and logical substitutions and changes may be made without departing from the scope of this disclosure. This Detailed Description, therefore, is not to be taken in a limiting sense, and the scope of various embodiments is defined only by the appended claims, along with the full range of equivalents to which such claims are entitled. 
         [0057]    Such embodiments of the inventive subject matter may be referred to herein, individually and/or collectively, by the term “invention” merely for convenience and without intending to voluntarily limit the scope of this application to any single invention or inventive concept if more than one is in fact disclosed. Thus, although specific embodiments have been illustrated and described herein, it should be appreciated that any arrangement calculated to achieve the same purpose may be substituted for the specific embodiments shown. This disclosure is intended to cover any and all adaptations of variations of various embodiments. Combinations of the above embodiments, and other embodiments not specifically described herein, will be apparent to those of skill in the art upon reviewing the above description.