Electrical testing of prited circuit boards employing a multiplicity of non-contact stimulator electrodes

Abstract

Apparatus for the electrical testing of electrical circuits including at least one array of non-contact stimulator electrodes having a multiplicity of individually controlled stimulator electrodes arranged to be linearly disposed adjacent a first side of an electrical circuit to be tested; a signal generator coupled to the at least one array arranged to supply an electrical stimulation signal to each of the stimulator electrodes; and at least two non-contact sensor electrodes, each having dimensions sufficiently large to overlay part of a conductor on the electrical circuit to be tested.

1 - 82 . (canceled)  
   
   
       83 . Apparatus for electrically testing electrical circuits comprising: 
 at least one array of non-contact stimulator electrodes including a multiplicity of individually controlled stimulator electrodes arranged to be linearly disposed adjacent a first side of an electrical circuit to be tested;    a signal generator coupled to said at least one array arranged to supply an electrical stimulation signal to each of the stimulator electrodes; and    at least two non-contact sensor electrodes, each sensor electrode having dimensions sufficiently large to overlay part of a conductor on said electrical circuit to be tested.    
   
   
       84 . Apparatus as claimed in  claim 83 , wherein said at least one of said two non-contact sensor electrodes is arranged to lie on a second side of said electrical circuit to be tested, opposite to said first side.  
   
   
       85 . Apparatus as claimed in  claim 83 , wherein said sensor electrodes are operative to correlate a signal to a particular non-contact stimulator electrode to provide spatial information.  
   
   
       86 . Apparatus as claimed in  claim 83 , wherein at least some of said electrical stimulation signals are at different frequencies.  
   
   
       87 . Apparatus as claimed in  claim 83  wherein said electrical stimulation signals are multiplexed.  
   
   
       88 . Apparatus as claimed in  claim 83 , wherein said at least two non-contact sensor electrodes are arranged to lie adjacent said at least one array of non-contact stimulator electrodes.  
   
   
       89 . Apparatus as claimed in  claim 88 , wherein said at least two non-contact sensor electrodes are arranged to lie on opposite side of said at least one array of non-contact stimulator electrodes.  
   
   
       90 . Apparatus as claimed in  claim 83 , wherein said at least two non-contact sensor electrodes includes at least one sensor electrode arranged to lie adjacent a second side of said electrical circuit to be tested, said second side being opposite said first side.  
   
   
       91 . Apparatus as claimed in  claim 83 , further comprising: 
 a separating detector arranged to receive an output from each of said non-contact sensor electrodes and being operative to correlate a signal to a particular non-contact sensor electrode;    a signal analyzer operative to receive said outputs and to analyze the outputs;    a comparator operative to compare said outputs to an expected signal; and    a report generator at least reporting the presence of defects in said electrical circuit to be tested.    
   
   
       92 . Apparatus as claimed in  claim 91 , wherein said defects included defects selected from a group of defects including: faulty conductor continuity, shorts between conductors, and breaks in conductors.  
   
   
       93 . Apparatus as claimed in  claim 83 , wherein said non-contact stimulator electrodes are configured to generate localized electromagnetic fields each stimulating different conductors on said electrical circuit to be tested.  
   
   
       94 . Apparatus as claimed in  claim 83 , wherein said non-contact stimulator electrodes are arranged to be scanned over said electrical circuit to be tested.  
   
   
       95 . Apparatus as claimed in  claim 83 , wherein said non-contact sensor electrodes are at least as large as said electrical circuit to be tested.  
   
   
       96 . A method for electrically testing electrical circuits, comprising: 
 stimulating conductors on an electrical circuit to be tested with a multiplicity of individually controlled stimulator electrodes linearly arranged adjacent a first side of said electrical circuit to be tested;    supplying an electrical stimulation signal to each of the stimulator electrodes; and    sensing a response to said stimulating with at least two non-contact sensor electrodes, each sensor having dimensions sufficiently large to overlay part of a conductor on said electrical circuit to be tested.    
   
   
       97 . The method as claimed in  claim 96 , further comprising correlating a signal to a particular non-contact stimulator electrode to provide spatial information.  
   
   
       98 . The method as claimed in  claim 97 , wherein said correlating comprises operating said stimulator electrodes at different frequencies.  
   
   
       99 . The method as claimed in  claim 97 , wherein said correlating comprises multiplexing said electrical stimulation signals.  
   
   
       100 . The method as claimed in  claim 96 , wherein sensing comprises sensing said response on said first side of said electrical circuit to be tested.  
   
   
       101 . The method as claimed in  claim 100 , wherein said sensing comprises sensing said response on opposite sides of said multiplicity of said non-contact stimulator electrodes.  
   
   
       102 . The method as claimed in  claim 96 , wherein sensing comprises sensing said response on a second side of said electrical circuit to be tested, said second side being opposite said first side.  
   
   
       103 . The method as claimed in  claim 96 , further comprising: 
 associating a signal with a particular non-contact sensor electrode;    analyzing outputs of said sensors;    comparing compare said outputs to an expected signal; and    reporting the presence of electrical defects in said electrical circuit to be tested.    
   
   
       104 . The method as claimed in  claim 103 , wherein said defects included defects selected from a group of defects including: faulty conductor continuity, shorts between conductors, and breaks in conductors.  
   
   
       105 . The method as claimed in  claim 96 , wherein stimulating comprises generating localized electromagnetic field stimulating a different conductor on said electrical circuit to be tested.  
   
   
       106 . The method as claimed in  claim 96 , further comprising scanning said non-contact stimulator electrodes over said electrical circuit to be tested.  
   
   
       107 . The method claimed in  claim 96 , wherein said non-contact sensor electrodes are at least as large as said electrical circuit to be tested.