Abstract:
A circuit board router ( 10 ) and method thereof. De-paneling of printed circuit boards ( 62 ) off a panel  860 ) is efficiently increased by a router ( 40 ) which is positioned at a location above the panel ( 60 ). A fixture positions the panel  860 ) below the router ( 40 ) on a base ( 16 ). A controller ( 64 ) activates a first drive mechanism ( 20 ), a second drive mechanism ( 26 ), and a third drive mechanism ( 32 ) to guide an X-arm ( 18 ), a Y-arm ( 24 ) and a Z-arm ( 10 ), respectively. The router ( 40 ), located on the Z-arm ( 30 ), moves downward to engage a router bit ( 42 ) to the panel ( 60 ) to depanel the printed circuit board ( 62 ) from the panel. A fixture chip ( 72 ), which has a preprogrammed pattern of the panel ( 60 ), is embedded inside the fixture ( 58 ). A radio frequency transmitter ( 80 ) transmits the pattern to a radio frequency receiver ( 82 ) that relays the pattern to the controller ( 64 ).

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
   This application claims priority to and the benefit of the filing date of U.S. Provisional Application No. 60/261,950, filed on Jan. 16, 2001. 

   FIELD OF THE INVENTION 
   The present invention relates to a router device. In particular, the present invention relates to a router device that automatically depanels individual printed circuit boards from a panel. 
   BACKGROUND OF THE INVENTION 
   In the industry, printed circuit boards (PCB&#39;s) when manufactured are assembled by affixing a plurality of PCB&#39;s to a panel. By affixing a plurality of PCB&#39;s to a panel, substantial savings of time, material and money have been obtained as handling a plurality of PCB&#39;s simplifies and speeds up the automated processing of the PCB&#39;s. As the commercial demands of PCB&#39;s in the electronics industry increases, the plurality of PCB&#39;s assembled on a single panel require more efficient handling by the processing equipment. 
   An important consideration in the processing of the PCB&#39;s is the removal of the individual PCB from the panel for further processing or installation into the finished product, such as a computer or other electronic equipment. Efficiently removing the PCB&#39;s from the panel allows more panels to be processed, resulting in economic gain. 
   Removing the PCB&#39;s from the panel is referred to as “depaneling” or “liberating” the PCB&#39;s from the panel. Methods presently used in the industry to depanel each individual PCB from the interconnected PCB&#39;s in the panel have typically included shearing, routing, break-away methods of routed tabs, scoring, perforation, and various punch and die techniques. 
   Routing employs cutting rout slots in the panel around individual PCB&#39;s to define the perimeter of the individual PCB. As such, the routing leaves support tabs around the perimeter for holding the individual boards in place. Such tabs are then cut, broken, or routed to remove each board. 
   Scoring utilizes grooving lines along portions of individual board perimeters. Such score lines are then used as weak areas to separate the board by breaking the PCB from the panel along the score lines. In addition, various perforations have been used to define the perimeters of the individual boards. Breaking along the lines of perforation is then used to depanel the individual boards. Other methods of depaneling include punch and die techniques wherein a custom made die is used to punch each individual board out of the panel. 
   These methods of depaneling contain deficiencies, however. The present scorers reduce the rigidity of the panel. Accordingly, the panels are prone to sagging during further processing after one of the PCB&#39;s is separated. As a result of the sagging, the subsequent PCB&#39;s are not as accurately processed. Perforation and scoring yield very poor quality edges. Accordingly, the edges cannot be held to close tolerances. Additionally, the punch and die method requires expensive tooling as the punch and die is custom made with respect to the panel. Thus, panels having different configurations require different punches and dies. Additionally, the tooling needs to be replaced with each new panel, requiring further downtime of the punch and die. 
   Thus, a need exists for a high volume and high speed depaneling of PCB&#39;s from panels containing a plurality of PCB&#39;s. A need also exists for a router which enables damage free depaneling of the PCB from the panel. Further, a need exists for a router that depanels the PCB from a location above the PCB. Additionally, a need exists for a router that can be programmed to read a panel configuration and depanel the PCB without changing any tooling. 
   Devices are known in the industry that accept a panel of PC boards and depanel the individual PC boards. U.S. Pat. No. 5,894,648, issued to Hill, discloses a depaneling apparatus that removes the individual PCB from the panel and automatically positions the separated PCB to a registration area. The depaneler then automatically moves the PCB from the registration area to a subsequent processing station. In this depaneler, the PCB is depaneld by a router that cuts the PCB from underneath the panel. 
   This depaneler contains deficiencies, however. Design constraints of an assembly line may not allow the routing mechanism to be underneath the panel. Further, locating the router under the area where the panel is to be processed limits access to the router. Thus, during maintenance or breakdowns, more time is needed to access the router, resulting in less operation time and increased maintenance costs. Further, in some assemblies, it may not be practical to automatically move the separated PCB to a further processing station. Further, the depaneler requires a loading track to position the panel for routing, which may not be practical with regard to the allowable workspace. 
   Another approach is disclosed in U.S. Pat. No. 4,742,615 issued to Lopez, which recites a routing method and apparatus. This device, however, positions the router underneath the panel and routs from below, which may be impractical due to workspace limitations. Further, this device can only rout one predetermined set of panels as opposed to adapting to rout panels with different configurations. 
   Another approach is disclosed in U.S. Pat. No. 5,067,229 issued to Nakamura, which recites a cutting device for electronic components. This cutting device also cuts from underneath the panel. Further, the device requires an identification pattern consisting of eight sections of coated and non-coated sections of the panel in order for the device to sense which type of panel is to be processed, adding to the complexity and cost of the cutting device. 
   OBJECTS OF THE INVENTION 
   It is therefore an object of the present invention to provide an apparatus that enables damage-free depaneling of a printed circuit board from a panel. 
   Another object of the present invention is to depanel the printed circuit board from a location above the printed circuit board. 
   Another object of the present invention is to provide an automatic program to program the routing pattern into a controller based upon the panel placed in the device. 
   Another object of the present invention is to provide a method of damage-free depaneling of a printed circuit board from a panel. 
   Still further objects and advantages will become apparent from a consideration of the following descriptions and drawings. 
   SUMMARY OF THE INVENTION 
   In one embodiment, the present invention comprises a circuit board router device to depanel a printed circuit board. The router device comprises a base positioned on top of a frame. Attached to the base is a router assembly. The router assembly comprises an X-arm to move the router spindle in the X axis, a Y-arm to move the router spindle in the Y axis, and a Z-arm to move the router spindle in the Z axis. The router assembly further comprises a router bit held by the spindle. 
   The router spindle is attached to the Z-arm to engage a panel from a location above the panel. The panel holds a plurality of PCB&#39;s as a single unit. Tabs connect the PCB&#39;s to the panel in which the panel is positioned within a fixture. The fixture is placed underneath the router spindle to engage a router bit against the tabs to depanel the PCB&#39;s from the panel. The routed tabs and panel are discarded through a base aperture located on the base. 
   The illustrated embodiment further comprises a controller to control a first drive mechanism, a second drive mechanism, and a third drive mechanism which drive the X-arm, the Y-arm and the Z-arm, respectively, to proper coordinates above the fixture. A display screen is connected to the frame, which is capable of programming the controller. The display screen is also capable of displaying diagnostic information of the router device. 
   In one embodiment, the router device is pre-programmable to rout a particular pattern of the panel. In this embodiment, a fixture chip is embedded within the fixture in which the fixture has an identifying mark to indicate which pattern of panel is being positioned in the fixture. The fixture chip mates with a radio frequency transmitter which relays the programmed pattern of the fixture chip to a radio frequency receiver. The radio frequency receiver in turns relays the programmed pattern to the controller. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a front elevation view of the circuit board router embodying principles of the invention; 
       FIG. 2  is a side elevation view of the router of  FIG. 1  embodying principles of the invention; 
       FIG. 3  is a perspective detail view of the circuit board router embodying principles of the invention; 
       FIG. 4  is a perspective view of the router of  FIG. 3  embodying principles of the invention; 
       FIG. 5  is a plan view of the fixture and populated panel of an embodiment of the invention; 
       FIG. 6  is a front elevation view of the circuit board router embodying principles of the present invention; 
       FIG. 7  is a perspective view of  FIG. 6  embodying principles of the present invention; 
       FIG. 8  is a detail view of the router spindle and router bit of an embodiment of the present invention; 
       FIG. 9  is a perspective detail view of  FIG. 8  embodying principles of the present invention; and 
       FIG. 10  is a plan view of the radio frequency transmitter and receiver embodying principles of the present invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Referring now to the accompanying drawings, a router device  10  of the type generally contemplated can either be electrically, pneumatically or hydraulically operated dependant upon the force necessary to carry out the depaneling process required. The router device  10  comprises a frame  12  supported by supports or stanchions  14 . The supports  14  may be adjustable to accommodate for different heights of the frame  12 , or to accommodate different levels of a floor  15 . The frame  12  is open underneath to allow access within the router device  10 . The frame  12 , however, may be closed to protect the area within the frame  12 . Further, the frame  12  has an access space  56  to hold electrical equipment. As shown in the illustrated embodiment of  FIG. 1 , the access space  56  includes a shelf with a handle  57 . In other embodiments, the access space  56  may comprise a drawer. 
   Positioned on top of the frame  12  is a base  16  which is of a generally square shape as shown in the illustrated embodiment of  FIGS. 1 and 2 . The base  16  is flat to provide a bed  36  or workspace. Attached to the base  16  is a router assembly  17 . The router assembly  17  comprises an X-arm  18  to move in an X axis, a Y-arm  24  to move in the Y axis, a Z-arm  30  to move in the Z axis, a router spindle  40 , and a router bit  42 . A router assembly mount  19  positions the router assembly  17  above the base  16 , as shown in  FIGS. 1 and 2 . 
   A panel  60  containing four sets of a printed circuit board (PCB)  62  is shown in  FIG. 5 . The panel  60  as known in the art holds each PCB  62  together as a single unit. Tabs  63  define the edges of the PCB&#39;s  62 . Tabs  63  connect each PCB  62  to the panel  60  and are depaneled during the routing process to release each PCB  62  from the panel  60 . Panel  60  becomes debris after the PCB  62  has been routed. Four sets of PCB&#39;s  62  are shown as exemplary, but one skilled in the art will recognize that the panel  60  may be comprised of any number of PCB&#39;s  62 . The panel  60  is capable of being attached to a fixture  58 , which serves as a support tray. The fixture  58  is removably attached on the base  16  as shown in  FIG. 6 . 
   In the illustrated embodiment, the Y-arm  24  is attached to and below the X-arm  18 , while the Z-arm  30  is attached to the X-arm  18 . The X-arm is attached perpendicular to the Y-arm  24 . Accordingly, the Z-arm  30  is attached perpendicular to the X-arm  18 . The X-arm  18  is attached to the Y-arm by a first mount  27 , while the Z-arm  30  is also attached to the X-arm  18  by a second mount  31 . The X-arm  18  and the Y-arm  24  are reciprocally moveable back and forth along the respective X and Y axes while the Z-arm  30  is reciprocally moveable up and down along the Z axis. As configured, any movement of the Y-arm  24  will result in movement of the X-arm  18  and the Z-arm  30  in the direction of the Y axis. Further, any movement of the X-arm  18  will result in movement of the Z-arm  30  along the X axis. It will be known to those in the art that the X-arm  18  and the Y-arm  24  directions are chosen arbitrarily, as rotating the base  16  by ninety degrees would result in the proper reciprocating movement along the proper denoted axis. 
   The first mount  27  is driven along the Y axis on the Y-arm  24  by a first drive mechanism  20 . In the illustrated embodiment, the first drive mechanism  20  is a motor. The first drive mechanism  20  may also comprise other drive mechanisms, such as (but not limited to), jack screws, springs, gears, and magnets. The first mount  27  travels in the direction along the Y-arm  24  along a first guide  22  illustrated as a track. The first guide  22  may however include, but is not limited to, a rail, a conveyor, a channel, a magnetic strip, an optical field, and a rack and pinion. 
   The second mount  31  is driven along the X axis on the X-arm  18  by a second drive mechanism  26 . In the illustrated embodiment, the second drive mechanism  26  is a motor. The second drive mechanism  26  may also comprise other drive mechanisms, such as, but not limited to, jack screws, springs, gears, and magnets. The second mount  31  travels in the direction along the X-arm  18  along a second guide  28  illustrated as a track. The second guide  28  may however include, but is not limited to, a rail, a conveyor, a channel, a magnetic strip, an optical field and a rack and pinion. 
   The third mount  33 , which carries the router spindle  40 , is driven along the Z axis on the Z-arm  30  by a third drive mechanism  32 . In the illustrated embodiment, the third drive mechanism  32  is a motor. The third drive mechanism  32  may also comprise other drive mechanisms, such as but not limited to, jack screws, springs, gears, and magnets. The third mount  33  travels in the direction along the Z-arm  30  along a third guide  34  illustrated as a track. The third guide  34  may however include, but is not limited to, a rail, a conveyor, a channel, a magnetic strip, an optical field and a rack and pinion. 
   The router spindle  40  is attached to the third mount  31  to engage the panel  60  from a location positioned above the panel  60 . The router spindle  40  is lowered along the Z-arm  30  to engage the panel  60 . The router spindle  40  rotates the router bit  42  to depanel the PCB  62  by routing the tabs  63  from the PCB  62 . A camera  68  is also attached to the Z-arm  30  by a camera mount  70  to aid a controller  64  during the depaneling process. In the illustrated embodiment, the camera  68  is connected to the controller  64  by flex tubing in order for the camera  68  to be flexible for panels  60  with different configurations. 
   Additionally, at least one base aperture  44  is positioned through the base  16  in order for the routed panel  60  and tabs  63 , which are now debris, to be discarded through the base aperture  44 . Additionally, a vacuum system (not shown) may also be connected adjacent the router bit  42  in order to collect the debris. 
   An access cover  52  covers most of the area above the base  16 . To allow visual operation and access of the router assembly  17 , an access cover aperture  54  is positioned on the front of the access cover  52 . The access cover aperture  52  is configured to allow access from the back of the access cover  52 . The access cover  52  may be removably fixed to the base  16 . 
   As shown in  FIGS. 3 and 4 , the controller  64  communicates with the first drive mechanism  20 , the second drive mechanism  26 , and the third drive mechanism  32  to coordinate the operations of the router spindle  40 . The controller  64  further provides on-line programming and diagnostic information of the router device  10 . The controller  64  may be a computer or similar device. The connections from the controller  64 , such as the electrical wires, are understood by those in the art. As shown in  FIG. 1 , a control panel  65 , which is attached to the frame  12 , can signal the controller  64  to activate. Additionally, a display screen  66  is provided which is capable of programming the controller  64  via a touch screen format. The display screen  66  can also display the current operation status of the router device  10 . 
   The display screen  66  is mounted on a display support  50  as shown in  FIG. 3 . The display support  50  may be adjustable to provide different viewing angles and different viewing heights of the display screen  66 . The display support  50  is attached to a vertical member  45 , which offsetably connects to the frame  12  by a bracket  49 , as shown in  FIGS. 3 and 4 . Attached to the top of the vertical member  45  is a signal  46  that indicates the status of the router device  10 . The signal  46  may send visual signals, such as illuminating lights, to depict different stages of operation. For example, one light may indicate that the router device  10  is in operation, while another light may indicate that the router device  10  is not in operation. Further, the signal  46  may send audio signals, such as different tones, to indicate the operation status of the router device  10 . 
   As shown in  FIG. 5 , a particular pattern exists between the PCB&#39;s  62  to be depaneld. As this pattern may vary according to the particular panel  60  disposed within the fixture  58 , the present invention is adapted to automatically program the controller  64  to rout to the particular pattern of the panel  60 . A fixture chip  72  is fixed into the fixture  58  in which the fixture  58  has an identifying mark  75  displayed to indicate the fixture chip  72  as shown in  FIG. 10 . The fixture chip  72  is preprogrammed with the particular pattern of the panel  60 . Thus, for example, if the panel  60  has a routing pattern # 1 , the fixture chip  72  is preprogrammed with routing pattern # 1 . Accordingly, the identifying mark  75  would indicate routing pattern # 1 . 
   The fixture chip  72  has leads (not shown) that mate with a cable  76  as shown in  FIG. 10 . The cable  76  connects to a radio frequency transmitter  80  that is positioned on the base  16 . The radio frequency transmitter  80  transmits the routing pattern to a radio transmitting receiver  82  which is also positioned on the base  16 . The radio transmitting receiver  82  transmits the routing pattern to the controller  64  to activate the routing spindle  40  on the panel  60 . 
   In an alternative embodiment, the fixture  58  has a chip (not shown) that communicates with a sensor (not shown) located on the base  16  that the fixture has been placed on the base  16 . The sensor (not shown) then communicates to the controller  64  to start the depaneling process. Thus, in this alternative embodiment, placing the fixture  58  on the base  16  causes the operation to start. 
   During operation, the access cover  52  is opened and the fixture  58  is placed on the base  16 . The panel  60 , which is populated with PCB&#39;s  62 , is placed into the fixture  58 . During manual operation, the fixture  58  is placed over the base aperture  44  but under the router assembly  17 . The camera  68  is then calibrated to the router spindle  40  location. Next, the thickness data of the PCB  62  is entered into the controller  64  along with the X-Y traverse speed data and the X-Y cut speed data of the router bit  42 . The router bit  42  may be replaced according to the thickness data. Next, the lower Z height data is entered to the controller  64  for the cut and the upper Z height for the travel data is also entered into the controller  64 . Further, the speed of the router spindle  40  is entered into the controller  64  along with the diameter of the router bit  42 . The required data may be entered via a keyboard (not shown) or via the display screen  66 . Alternatively, the required data may be downloaded from a source such as a floppy disc or CD ROM into the controller  64 . 
   Further, the fixture  58  may contain the fixture chip  72 . In this embodiment, the fixture chip  72  transmits the required data of the panel  60  via the radio frequency transmitter  80  to the radio frequency receiver  82  via the cable  76 . The radio frequency receiver  82  transmits the required date to the controller  64  to start the depaneling process. 
   In an alternative embodiment, the camera  68  is “taught” proper start and stop cut locations on the panel  60 . In this embodiment, the camera  68  is positioned to a start location and the start location is recorded by the controller  64 . The camera  68  is then positioned to a stop location and the stop location is recorded by the controller  64 . Each PCB  62  is mapped on the panel  60  according to the camera  68 . In a further alternative embodiment, the router spindle  40  is manually moved to each start location and each stop location to map the pattern of the PCB&#39;s  62 . The start and stop locations are known as a fiducial and teach location. This information is then recorded by the controller  64  to start the depaneling process. This method is continued to teach the controller  64  all cut locations. 
   Thus, once the designated router program is selected to record the required data into the controller  64 , the controller  64  positions the router spindle  40  to the correct location by activating the first drive mechanism  20 , the second drive mechanism  26 , and the third drive mechanism  32 , which correctly positions the first mount  27  along the first guide  22 , the second mount along the second guide  28 , and the third mount  33  along the third guide  34 , respectively. The router spindle  40  travels down the Z-arm  30  by the third mount  33  to engage the panel  60 . 
   The controller  64  then activates the router bit  42  to route the tabs  63  to free the PCB  62  from the panel  60 . The controller  64  moves the router bit  42  to the next location until all PCB&#39;s  62  are free from the panel  60 . During the depaneling operation, the vacuum system (not shown) may be activated to collect the debris of the tabs  63  and panel  60 . After the depaneling is complete, the router bit  42  is terminated. At this time, the access cover  52  is lifted and the PCB&#39;s  62 , which are now depaneled, are lifted out off the base  16 . Any leftover tab  63  or panel  60  may be discarded through the base aperture  44 . A new panel  60  is then place on the fixture  58  in order for the routing sequence to begin again. 
   Although the foregoing detailed description of the present invention has been described by reference to various embodiments, and the best mode contemplated for carrying out the present invention has been herein shown and described, it will be understood that modifications or variations in the structure and arrangement of these embodiments, other than those specifically set forth herein, may be achieved by those skilled in the art, and that such modifications are to be considered as being within the overall scope of the present invention.