DIN EN 61189-3-719:2016-12

This Part 3-719 of the 61189 series of standards specifies a test method for monitoring the resistance of single plated-through hole (PTHs) in printed circuit boards in order to determine the long-term reliability of the PTHs under thermo-mechanical loads caused by temperature cycling. The test panels are coupons of N-layer printed circuit boards. Unless described in the corresponding specification, a test coupon shall include four individual through holes for connecting the first (top, outer) layer to the Nth (bottom, outer) layer (via hole L1 - via hole LN), with the corresponding labeling, and four individual through holes for connecting the second layer to the third layer (via hole L2 - via hole L3) or layer (N2) to layer (N1), with the corresponding labeling. In addition, the test coupon shall include a reference conductive pattern on an outer layer to compensate for possible temperature variations over different temperature cycles and resistance changes of the conductors due to aging during testing. The length of the conductive pattern of the reference structure is not relevant, but it is recommended that a length equal to the length of the conductive patterns connecting the via holes to the termination points be used and that the conductive pattern of the reference structure extend across the test coupon to ensure that the reference structure is representative of the given test coupon. All structures shall have connections for four-wire resistance measurement. To limit self-heating, the cross-section of the conductive patterns shall be at least two times larger than the cross-section of the PTHs. The responsible committee is DKE/K 682 "Aufbau- und Verbindungstechnik für elektronische Baugruppen" ("Packaging and interconnection technology for electronic assemblies") of the DKE (German Commission for Electrical, Electronic and Information Technologies) at DIN and VDE.