METHOD MEASURING RESISTANCE OF CONDUCTORS IN MULTILAYER PRINTED CIRCUIT BOARDS AND DEVICE FOR ITS IMPLEMENTATION Russian patent published in 2000 - IPC

FIELD: instrumentation, nondestructive inspection of printed assembly of multilayer printed circuit boards. SUBSTANCE: method measuring resistance of conductors of multilayer printed circuit boards is based on division of printed circuit board into N unspecified groups of metallized holes, on supply of stabilized current to first points of connection of each of measured sections of circuits, on supply of zero potential to second points of connection of these sections of circuit and on measurement of voltage drop. In this case current contacts are linked on one side of metallized junctions of multilayer printed circuit board and potential contacts - on the other side of same metallized junctions to form collection of all elementary sections of circuits of multilayer printed circuit board subject to test. Formation of collections L and M of measured sections of circuits is carried out to conduct first cycle of simultaneous measurement of resistance of these sections of circuits. If each of L measured sections of circuits has connection points inside proper group of metallized holes voltage drops between first and second connection points of L measured sections of circuits are measured simultaneously, where L=0, 1,...N. If each of M measured sections of circuits, where M=0, 1...,(N-L)/2, has connection points between groups of metallized holes, that is, first point of each of M measured sections of circuits belong to group L+2M-1 and second point- to group L+2M then voltage drops are determined across measured sections of circuits by subtraction of results of simultaneously measured voltage drops correspondingly in first and second points of measured sections of circuits with reference to common bus. Then collections L and M of measured sections of circuits are formed to conduct next cycle of simultaneous measurement of resistance of these sections of circuits. Device to measure resistance of conductors of multilayer printed circuit boards incorporates N measurement-commutation modules for connection to N groups of metallized holes ( connection points ) into which tested multilayer printed circuit board is divided at will, N four-wire communication lines, where N=1, 2, 3,..., adapter, interface and microcomputer. N four-wire communication lines provide for connection to N measurement-commutation modules of L+M measured sections of circuits of tested multilayer printed circuit board. EFFECT: enhanced speed of measurement of resistance of conductors of multilayer printed circuit board by way of simultaneous measurement of resistance in L+M tested sections during one measurement cycle. 2 cl, 3 dwg