Mechanical, thermal and electrical analysis of a compliant interconnect

• Published in: The Ninth Intersociety Conference on Thermal and Thermomechanical Phenomena In Electronic Systems (IEEE Cat. No.04CH37543) Vol. 1; pp. 618 - 623 Vol.1
• Main Authors: Galloway, J., Syed, A., WonJoon Kang, Jin Young Khim, Cannis, J., YunHyeon Ka, Seungmo Kim, TaeSeong Kim, GiSong Lee, SangHyun Ryu
• Format: Conference Proceeding
• Language: English
• Published: Piscataway NJ IEEE 2004
• Subjects: Applied sciences; Design. Technologies. Operation analysis. Testing; Electric resistance; Electric shock; Electrical resistance measurement; Electronic equipment and fabrication. Passive components, printed wiring boards, connectics; Electronics; Electronics packaging; Exact sciences and technology; Fatigue; Integrated circuits; Plastic packaging; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Thermal conductivity; Thermal loading; Thermal resistance; Wafer scale integration; Warping; Thermal cycle; Plastic packaging; Fatigue fracture; BGA technology; Chip scale packaging; Integrated circuit bonding; Thermal resistance; Electronic packaging; Thermal conductivity; Resistor; Wafer; Electrical characteristic; Fatigue life; Eutectic alloy; Thermal behavior; Durability; Polymer; Thermal fatigue; Solder bump; Interconnection; First order; Soldered joint; Integrated circuit; Thermal analysis; Reliability; Gain
• ISBN: 9780780383579; 0780383575
• DOI: 10.1109/ITHERM.2004.1319233

Ball grid array (BGA) package styles use solder balls as an electrical interconnect between packages and application boards. Solder balls are rigid and tend to fracture under thermal fatigue and/or shock loading. Metalized polymer spheres (MPS) offer a more compliant interconnect, compared to solder balls, thereby increasing the thermal cycling fatigue life. A reduction in thermal and electrical performance can be expected for MPS interconnects as a result of its lower thermal conductivity and an higher electrical resistance. A 5% and an 8% increase in MPS thermal resistance was measured for a carrier array ball grid array (CABGA) package and a plastic ball grid array (PBGA) package, respectively, compared to eutectic solder balls. However, this small reduction was offset by large gains in the solder joint life. A 4.5X increase in the mean thermal fatigue life was measured for a wafer level chip scale package (WLCSP) using MPS interconnects compared to eutectic solder balls. A first-order model showed that eutectic solder balls provide greater process margin in the presence of package and board warping compared to MPS interconnects.