Patent ID: 9607172
Date: 2017-03-28
CPC Classifications: G01N,G01R,G06F,H05K

Claim:
1. A method, implemented by at least one computer, for fabricating, for an integrated circuit (IC) chip attached to a surface of a printed circuit board (PCB), a security apparatus including a Wheatstone bridge circuit, the method comprising: creating, through the use of a first etching process controlled by the at least one computer, on the surface of the PCB, four sets of at least two electrically conductive pads; depositing, through the use of a first deposition process controlled by the at least one computer, a first conformal coating layer that is electrically insulative upon at least the surface of the PCB and exposed surfaces of the IC chip; creating openings, through the use of a second etching process controlled by the at least one computer, corresponding to the four sets of at least two electrically conductive pads, in the first conformal coating layer; depositing, through the use of a second deposition process controlled by the at least one computer, a second conformal coating layer that is X-ray opaque, optically opaque and electrically resistive onto the first conformal coating layer; and creating, through the use of a third etching process controlled by the at least one computer, four resistors of the Wheatstone bridge circuit by removing material to divide the second conformal coating layer into four regions.