GROWTH KINETICS OF INTERMETALLIC COMPOUNDS IN CHIP SCALE PACKAGE SOLDER JOINT

摘要: Department of Electronic Engineering, and *Department Physics Materials Science,City University Hong Kong, People’s Republic China(Received May 18, 2000)(Accepted in revised form August 2000)Keywords: Solder joint; Intermetallic; Aging; Kinetics; FatigueIntroductionAs the trend requirements electronic packaging is toward higher I/O, greater performance, higherdensity, lighter weight, use area array technology expected to increase. The typeof packaging, such as ball grid (BGA), chip scale package (CSP), Flip Chip, provides theultimate high I/O-density count with superior electrical very small size. Themechanical properties solder joint are recognized one critical factors that determine theirreliability lifetime [1–5]. During soldering, formation intermetallic compounds (IMCs) atsolder/substrate interface inevitable ensures a good metallurgical bond. However, during storageand field service, growth IMCs will influence strength joints result inmechanical failure [6–10]. Our recent research shows fatigue ofsolder decreases linearly increasing square root layer thickness [11]. Since theintermetallic responsible for failures, attention has be paid effect IMCsgrowth on reliability microelectronic assemblies.This paper discusses Ni-Sn/Cu-Sn kinetics soldered platedAu/Ni FR-4 printed circuit board (PCB), which most commonly used substrate finepitch packaging. kinetic model describing predicting IMC can usedto estimate lifetime, according relationship withvibration cyclic bend fatigue.Experimental ProceduresIn this experiment, CSP46-T.75 Sn/Pb-eutectic was placed andsoldered boards using high-speed flexible mounter (CASIO YCM-5500V) anda 5-zone N