Title :
Reliability of lead-free copper columns in comparison with tin-lead solder column interconnects
Author :
Park, S.B. ; Joshi, Rahul ; Goldmann, Lewis
Author_Institution :
Dept. of Mech. Eng., State Univ. of New York, Binghamton, NY, USA
Abstract :
The thermo mechanical behavior of the ceramic lead-free copper column grid array (CuCGA) package has bee characterized under accelerated thermal cycling using high sensitivity moire interferometry and compared with conventional ceramic tin-lead column grid arrays (CCGA). Unlike tin-lead columns, where the failure occurs at the column near the top of the solder fillet and through the thickness of the column, in the CuCGA, the failure is found to occur first in the solder fillet along the periphery of the copper column that propagates along the boundary of the column and solder fillet. The accumulated plastic deformation per cycle is bigger in tin-lead columns compared to the copper columns. A deformation mechanism is provided to explain the nature of this failure.
Keywords :
ceramic packaging; circuit reliability; copper; lead alloys; life testing; light interferometry; moire fringes; plastic deformation; reflow soldering; thermal management (packaging); tin alloys; Cu; SnPb; accelerated thermal cycling; accumulated plastic deformation per cycle; column grid array package; deformation mechanism; high sensitivity moire interferometry; isothermal load; lead-free copper columns; package bending; reliability; solder fillet; thermomechanical behavior; tin-lead solder column interconnects; Acceleration; Capacitive sensors; Ceramics; Copper; Electronic packaging thermal management; Environmentally friendly manufacturing techniques; Lead; Microelectronics; Optical interferometry; Tin;
Conference_Titel :
Electronic Components and Technology Conference, 2004. Proceedings. 54th
Print_ISBN :
0-7803-8365-6
DOI :
10.1109/ECTC.2004.1319319
