In conventional ETM (Etched Tri-Metal) circuit structures a pin connector in which the pin (30) is etched from the ETM substrate (16) and the mating cavity (32) is etched from the ETM substrate (18) to be mated. The connector utilizes the subtractive ETM structure processing to define any one of several pin-cavity configurations. The pin (30) serves as an anchor with the metallurgical bonds with solder (34) in the cavity (32) that forms on the copper surfaces (24,26) of the ETM circuit structures (16,18) to give good mechanical strength to the connection. In particular four different configurations of interconnections are shown and described.