Abstract:
An apparatus for retaining and cleaning a circuit board array, which comprise a fixture having a generally elongated connecting surface and one or more terminating open ends, which may optionally integrate a hollow element, creating an aperture in the fixture adjacent to a tab on the circuit board array, wherein the terminating open ends extend toward a machine component having at least one cavity extending through the topside of the machine component, and a vacuum system connected to the cavity, wherein the vacuum system applies suction through the cavity and the terminating open ends.

Description:
FIELD OF THE INVENTION  
         [0001]    This invention relates to circuit board routing fixtures. More particularly, this invention relates to vacuum systems to remove dust from a circuit board.  
         BACKGROUND OF THE INVENTION  
         [0002]    The manufacture of circuit boards involves the production of a multitude of circuit boards manufactured from a single array, referred to as a circuit board array. The circuit board arrays are manufactured, tooled, and populated with electronic devices, and then cleaved into individual circuit boards so that the individual circuit boards can be assembled into a desired application. The process of removing individual circuit boards from a circuit board array is commonly referred to as de-paneling. One of the methods of de-paneling boards is routing. Circuit board routing is the process by which a number of tabs on a circuit board array are cleaved in order to singulate one circuit board from another circuit board and/or from the excess material (scrap) that may be adjacent to the circuit board. The tabs on the connected circuit board array are routed by a rotating mechanism containing an appropriate bit. The bit is positioned in an opening at the perimeter of the circuit board adjacent to the tab to be routed. The bit moves through the tab and grinds out the tab creating dust and debris, which must be removed.  
           [0003]    Circuit board routing uses a fixture to locate and hold the circuit board while the circuit board is being routed. The fixture keeps the circuit board from moving during the routing process. As a circuit board is routed, a vacuum system is used to collect dust created during the routing operation. For dust collection to be effective, the suction created by a vacuum system must be concentrated at the area being routed. A vacuum system creates a space where the pressure is below normal atmospheric pressure, and has a practical result of imposing a suction on that space. A vacuum system applied to a small surface area has a greater suction velocity (pull) then when the same vacuum system is applied to a larger surface area. However, concentrating a vacuum system at the point of the routing operation becomes much more difficult when the circuit board is highly populated with electronic devices, such as integrated circuits, capacitors, resistors and other components.  
           [0004]    Current vacuum systems apply suction over a broad surface area of the circuit board array and are unable to sufficiently remove the dust that accumulates in the spaces surrounding where the tabs have been routed. The resulting accumulation of dust can have a detrimental impact on the functionality of the electrical devices housed in the circuit board and/or create environmental concerns due to airborne dust.  
           [0005]    As a result, it was desirable to provide an improved vacuum system employed to remove dust from circuit boards.  
         SUMMARY OF THE INVENTION  
         [0006]    The present invention discloses an improved vacuum system. In one embodiment, a fixture is integrated with a vacuum system, which concentrates the vacuum system&#39;s suction at the underside of the circuit board directly to areas where the tabs are cleaved. The fixture may further comprise hollow elements, which are localized at each tab on the circuit board array that will be routed. An open end on the bottom of the hollow elements extends into a terminating open end of the fixture, which extends into a cavity underneath the fixture, while the other open end at the other end of the hollow element contacts the surface area surrounding the tab that will be cleaved. The vacuum system applies suction to the cavity and up through the hollow elements.  
           [0007]    The vacuum system applies suction pressure to the cavity and hollow elements as the tabs on the circuit board array are routed. The hollow elements are substantially perpendicular to the circuit board array, and as a result, each hollow element is aligned substantially perpendicular under each tab to be routed on the circuit board array. These hollow elements, incorporated into the fixture, apply suction on the underside of the routed tabs. Consequently, each circumference or perimeter, which surrounds the individual tabs to be cleaved, ensures that the dust is effectively removed. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]    [0008]FIG. 1 is a perspective view of an exemplary circuit board array (CBA) comprising sixteen individual circuit boards, with the CBA installed on an embodiment of a fixture, and wherein the fixture is installed on a fixture adapter in accordance with an embodiment of the present invention.  
         [0009]    [0009]FIG. 2 is a top planar view of an exemplary CBA housing six individual circuit boards.  
         [0010]    [0010]FIG. 3 is a top planar view illustrating the CBA of FIG. 1 mounted on a traditional fixture.  
         [0011]    [0011]FIG. 4 is a bottom planar view of an exemplary traditional fixture illustrating areas where suction is applied.  
         [0012]    [0012]FIG. 5 is a top planar view of a fixture in accordance with an embodiment of the present invention, illustrating the surface areas where suction is applied.  
         [0013]    [0013]FIG. 6 is a top planar view of a CBA with etched hollowed out space prior to tabs being cleaved.  
         [0014]    [0014]FIG. 7 is a top planar view of the CBA of FIG. 5, illustrating terminating open ends localized at a tab to be routed, and wherein each terminating open end has a circumference or perimeter sufficient to surround each tab.  
         [0015]    [0015]FIG. 8 is a side planar view of a fixture with hollow elements projecting out of the fixture.  
         [0016]    [0016]FIG. 9 is a top planar view of six circuit boards in a CBA on a fixture with tabs surrounded by terminating open ends.  
         [0017]    [0017]FIG. 10 is a perspective view of a fixture adapter installed on a machine top plate having one large aperture through which the suction of the vacuum system moves through.  
         [0018]    [0018]FIG. 11 is a perspective view of an embodiment of a fixture installed on a fixture adapter. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0019]    While the present invention is susceptible of embodiment in varied forms, what is shown in the drawings will hereinafter be understood to be a preferred embodiment of the present invention. The present disclosure is to be considered as setting forth an exemplification of the invention, which in no way is intended to limit the invention to the specific embodiment illustrated below. In referring to the drawings, like reference numerals and letters indicate like parts throughout the several drawings.  
         [0020]    [0020]FIG. 1 shows an exemplary apparatus for circuit board routing  10 . In this embodiment, a sixteen CBA  20  is shown installed on a fixture  30 , which is a substantially cylindrical element fixture  30  in this embodiment. However, there are a variety of fixtures  30  which can be utilized in the present application. The fixture  30  is installed on a top portion of a fixture adapter  40 . Fixture  30  comprises a generally elongated connecting surface  31  and at least one, and preferably, a plurality of supports  32  that are connected to and extend transverse from the connecting surface  31 . In this embodiment, the supports  32  (hereinafter referred to as “hollow elements”) are substantially cylindrical hollow elements. These hollow elements are positioned substantially perpendicular to the connecting surface  31 . The hollow elements  32  are generally elongated with their shape defined by the terminating open end  33  of the connecting surface  31 . The terminating open end  33  is a cut-through creating an aperture in the fixture  30 . The terminating open end  33  has a defined circumference or perimeter, which allows vacuum suction to be localized to a particular location on the circuit board. The hollow elements  32  can take on a number of shapes, including but not limited to, squares or rectangles, all of which extend transverse from the connecting surface  31   
         [0021]    In one embodiment, the hollow elements  32  have a first and second open end  35 , whose openings are defined by the perimeter or circumference of the terminating open end  33 . In this embodiment, the underside of the CBA  20  rests across the hollow elements  32 . In addition, the present embodiment shows, one or more standing pins  34 , which are substantially cylindrical, connected to, and extending perpendicularly transverse from the connecting surface  31 . In the present embodiment, a routing machine  70 , of which any variety known in the art may be used, is utilized to route the CBA  20 .  
         [0022]    In another exemplary embodiment, drilling directly through the fixture  30  at the tab locations creates the terminating open end, and, no hollow elements  32  are installed on the fixture. This particular embodiment allows the CBA to rest directly on the fixture  30 , as vacuum suction is localized directly through the terminating open ends  33 .  
         [0023]    [0023]FIG. 2 shows generally, an overhead view of an exemplary CBA  20 , with tabs  24  positioned throughout the CBA  20 . The CBA  20  includes etchings  26  for six individual circuit boards  22 , and scrap  28  between the six circuit boards  22 . The etchings  26  carve through the CBA  20  leaving only the tabs  24  holding the six circuit boards  22  to the scrap  28 .  
         [0024]    [0024]FIG. 3 is an overhead view illustrating, generally, CBA  20  a fixture  30  in accordance with an embodiment of the present invention, and open area under each tab  24 .  
         [0025]    [0025]FIG. 4 is a bottom view of a fixture  30 . FIG. 4 illustrates surface areas d, e, f, and g that are suctioned by a vacuum system  50 , which is illustrated in FIG. 8 in accordance with an embodiment of the present invention. In this embodiment, suction is applied generally to the surface areas d, e, f, and g.  
         [0026]    [0026]FIG. 5 is an overhead view of surface areas a, b and c suctioned by a preferred embodiment of the vacuum system  50 . A hollow element  32  or terminating open end  33  is adjacent to each of surface areas a, b and c. Suction is applied through the hollow element  32  or terminating open end  33  to each of areas a, b and c. The circumference or perimeter  36  of each hollow element  32  or terminating open end  33  is preferably sufficient to surround the length of the tabs  24  of FIG. 2. The surface areas a, b and c correspond to the tabs  24  on the printed CBA  20  shown in FIG. 6.  
         [0027]    [0027]FIG. 6 shows an overhead view of CBA  20  and tabs  24  to be cleaved. The etchings  26  are located in this illustration throughout the outer perimeter of the CBA  20 , and when the tabs  24  are cleaved, four circuit boards  22  are singulated from one another.  
         [0028]    [0028]FIG. 7 is an overhead view illustrating the location of the terminating open ends  33  on a multiplicity of tabs  24 . The terminating open ends  33  have a circumference or perimeter  36 , which surrounds each of the tabs  24  to be cleaved. Each individual circumference or perimeter  36  of each of the terminating open ends  33  is preferably large enough in size to engulf an individual tab  24 . Further, the tabs  24  in this embodiment have varying lengths, and consequently the corresponding terminating open ends  33 , preferably have different circumferences or perimeters. The suction from the vacuum system  50  of FIG. 8 is preferably concentrated through one or more of the terminating open ends  33 , and more preferably, through each one of the terminating open ends  33  directly to the tabs  24 , which are cleaved by the routing machine  70  of FIG. 1. As can be seen in the figures, the length of the individual tabs  24  is substantially the same as the diameter across the circumference  36  of each of the terminating open ends  33  in this embodiment. This allows for an optimal suction velocity to pass through the individual terminating open ends  33 , and be directly applied to the area where the routing process is taking place.  
         [0029]    [0029]FIG. 8 is a side planar view illustrating a fixture  30 , with hollow elements  32  integrated and channeled through terminating open ends  33  of the fixture  30 . Each of the multitude of hollow elements  32  preferably pass into the terminating open ends  33  fixture  30  and extend through the aperture created by terminating open ends  33 , in order to feed into the cavity  62 , which is illustrated in FIG. 10. In this embodiment the hollow elements  32  are flush with the bottom of the fixture  30 , and connected perpendicular to the connecting surface  31 . In some cases, however, the hollow elements may be above or below the bottom of the fixture  30 . Vacuum system  50  is shown positioned underneath the fixture  30  in FIG. 8, and a vacuum hose  52  extends from the vacuum system and integrates with the fixture  30 , as will be described in more detail in FIG. 10. FIG. 8 also illustrates the first open end  33  of the hollow element  32 .  
         [0030]    [0030]FIG. 9 shows another overhead view of CBA  20 , having the same CBA  20  as in FIGS. 2 and 3, positioned on fixture  30 . The figure shows six separate circuit boards  22 , which are singulated by the routing process, and the resulting scrap  28  is preferably disposed. FIG. 9 further illustrates the circumference or perimeter  36  of the hollow elements  32  or terminating open ends  33  in relation to the length of the tabs  24 . The diameter or length of the open ends of the hollow elements  32  or terminating open ends  33  are preferably substantially similar to the length of the tabs  24 . Each terminating open end  33 , or hollow element  32  is still large enough to surround the tabs  24 . Further, the first open end  35  of FIG. 8 is large enough to surround the tabs  24 .  
         [0031]    [0031]FIG. 10 shows an exemplary fixture adapter  40  installed on machine top plate  60 . The machine top plate  60  has a cavity  62 . The cavity  62  has vacuum hose  52  connected on the underside of the machine top plate  60 , and applies suction through the cavity  62 , and then up through the terminating open ends  33 , and then through the hollow elements  32 . The vacuum system  50  applies suction to the underside of the fixture  30  when the fixture  30  is installed on fixture adapter  40 .  
         [0032]    [0032]FIG. 11 shows a preferred embodiment of the fixture  30  installed on the top surface of the fixture adapter  40 . In this embodiment, thirty-two hollow elements  32 , and four standing pins  34  flanking the outside rows of the hollow elements  32  are provided, although as should be understood, other numbers of elements  32  and standing pins  34  can also be provided where desired. The standing pins  34  provide support when a CBA  20  is placed on top of the hollow elements  32 . In operation, when the vacuum system  50  is utilized, it applies suction through the terminating open ends  33  and up through hollow elements  32  and down into the cavity  62 , as illustrated in FIG. 10. Also, this embodiment shows the first open end  35 , of the hollow element  32 , through which suction is applied.  
         [0033]    The components illustrated in the exemplary embodiments can be comprised of a number of suitable materials. The fixture plate, fixture adapter, and machine top plate can be comprised of, individually or in combination, steel, aluminum, titanium alloy, or any other of a number of materials, which exhibit the aforementioned materials characteristics. In a preferred embodiment the fixture plate is comprised of aluminum. The hollow elements can be comprised of any of a number of materials including steel, aluminum, and those exhibiting plastic qualities, such as polyethylene, and also material such as Teflon, Delrin or nylon. The CBA described in the exemplary embodiments of this invention is comprised of materials well understood and recognized in the art.  
         [0034]    The above description and the views and materials depicted by the figures are for purposes of illustration only and are not intended to be, and should not be construed as, limitations on the invention.  
         [0035]    Moreover, certain modifications or alternatives may suggest themselves to those skilled in the art upon reading of this specification, all of which are intended to be within the spirit and scope of the present invention as defined in the attached claims.