Simple fiducial marking for quality verification of high density circuit board connectors

Abstract

A printed circuit board with a printed pattern of fiducial marks on a first side of the printed circuit board including a first indicia including a right triangle with its base parallel to a first edge of the board and an alignment mark adjacent thereto, and a second indicia including a right triangle with its base parallel to a second edge of the board opposite said first edge, and an alignment mark adjacent thereto.

1 . A printed circuit board comprising: 
 a printed pattern of fiducial marks on a first side of the printed circuit board including a first indicia including a right triangle with its base parallel and adjacent to a first edge of the board and an alignment mark adjacent thereto, and a second indicia including a right triangle with its base parallel and adjacent to a second edge of the board opposite said first edge, and an alignment mark adjacent thereto.    
     
     
         2 . A printed circuit board as defined in  claim 1 , further comprising a plurality of connector contact areas extending along a third edge of said board between said first edge and said second edge.  
     
     
         3 . A printed circuit board as defined in  claim 2 , wherein the alignment mark has an edge adjacent said right triangle extending substantially parallel to the edge of the board, with the right triangle disposed between the alignment mark and the respective edge of the board.  
     
     
         4 . A planar printed circuit board having a first edge, a second edge opposite said first edge, and a third edge extending between said first and second edge; and 
 a printed circuit pattern imprinted on a first side of said circuit board using a mask pattern including a plurality of connector contact areas extending along said third edge and a first indicia including a right triangle with its base parallel and adjacent to a first edge of the board and an alignment mark adjacent thereto, and a second indicia including a right triangle with its base parallel and adjacent to a second edge of the board opposite said first edge, and an alignment mark adjacent thereto.    
     
     
         5 . A planar printed circuit board as defined in  claim 4 , wherein the printed circuit pattern has a predetermined specified width between said first and second edge, and a portion of at least one of the right triangles extends on the mask beyond said specified width so that an optimally dimensional circuit board has a truncated right triangle imprinted upon it.  
     
     
         6 . A planar printed circuit board as defined in  claim 5 , wherein the specification for a properly printed and routed board has the apex of each right triangle disposed between the upper and lower edges of the adjacent alignment mark.  
     
     
         7 . An optical transceiver for converting and coupling an information-containing electrical signal with an optical fiber comprising: 
 a housing including a fiber optic connect adapted for coupling with an external optical fiber for transmitting and/or receiving an optical communications signal;    a rigid printed circuit board in the housing including an edge forming a connector for coupling with an external electrical cable or information system device and for transmitting and/or receiving an information-containing electrical communications signal; and    a first indicia including a right triangle with its base parallel and adjacent to a first edge of the board and an alignment mark adjacent thereto, and a second indicia including a right triangle with its base parallel and adjacent to a second edge of the board opposite said first edge, and an alignment mark adjacent thereto, for assuring the accuracy and alignment of the electrical contacts of the connector.    
     
     
         8 . An optical transceiver as defined in  claim 7 , further comprising a plurality of connector contact areas extending along a third edge of said board between said first and second opposed edges.  
     
     
         9 . A transceiver as defined in  claim 7 , wherein the printed circuit board is printed using a mask with a pattern of fiducial marks with a predetermined specified distance to the ideal or optimum location of said first and second edge, and the right triangle indicia fiducial mark extends on the mask beyond said specified board width so that an optimally dimensional circuit board has smaller right triangles imprinted upon it than the right triangle indicia on the mask.  
     
     
         10 . A transceiver as defined in  claim 7 , wherein the specification for a properly printed and routed board has the apex of each right triangle disposed between the upper and lower edges of the adjacent alignment mark.  
     
     
         11 . A method of qualifying the accuracy of a printed circuit board comprising: 
 providing a printing mask pattern for a first side of the printed circuit board with a first spaced indicia including a right triangle with its base parallel and adjacent to a first edge of the board; and a second spaced indicia including a right triangle with its base parallel and adjacent to a second edge of the board opposite said first edge;    printing a layer of visually conspicuous material on a printed circuit board using said mask pattern;    determining the position of the apex of one indicia with respect to a corresponding alignment mark on the printed circuit board; and    based upon such position against a qualification criteria, accepting or rejecting the board.    
     
     
         12 . A method as defined in  claim 11 , wherein a plurality of boards are implemented on a panel and further comprising separating the board from the panel prior to the determining step.  
     
     
         13 . A method as defined in  claim 11 , wherein the method of separating includes routing.  
     
     
         14 . A method as defined in  claim 11 , wherein the determining step is performed by visual inspection of the first and second sides of the board by an operator.