Thermal cycling reliability of leadfree chip resistor solder joints

The solder joint reliability of ceramic chip resistors assembled to laminate substrates has been a long time concern for systems exposed to harsh environments. In this work, the thermal cycling reliability of several 2512 chip resistor leadfree solder joint configurations has been investigated. In an initial study, a comparison has been made between the solder joint reliabilities obtained with components fabricated with both tinlead and pure tin solder terminations. In the main portion of the reliability testing, two temperature ranges 40125C and 40150C and five different solder alloys have been examined. The investigated solders include the normal eutectic SnAgCu SAC alloy recommended by earlier studies 95.5Sn3.8Ag0.7Cu, and three variations of the leadfree ternary SAC alloy that include small quaternary additions of bismuth and indium to enhance fatigue resistance.