Dynamical IMC-growth calculation. Issue 9 (August 2015)

• Record Type: Journal Article
• Authors: Meinshausen, L.; Weide-Zaage, K.; Frémont, H.
• Is Part Of: Microelectronics and reliability. Volume 55:Issue 9/10(2015)
• Page Start: 1832
• Page End: 1837
• Publication Date: 2015-08
• Subjects: Simulation -- IMC growth -- Migration -- Reliability -- Packaging and assembly -- Package on package; Electronic apparatus and appliances -- Reliability -- Periodicals; Miniature electronic equipment -- Periodicals; Appareils électroniques -- Fiabilité -- Périodiques; Équipement électronique miniaturisé -- Périodiques; Electronic apparatus and appliances -- Reliability; Miniature electronic equipment; Periodicals; 621.3815
• DOI: 10.1016/j.microrel.2015.06.052
• Languages: English
• ISSNs: 0026-2714

Abstract

Abstract: Material movement between solder joints and their contact pads leads to the formation of intermetallic compounds at the contact surfaces. Concentration gradients are responsible for this material movement. The intermetallic compound growth during temperature storage and AC/DC electromigration tests on 12 × 12 mm Amkor® PoP with SnAg3.0 Cu0.5 ball grid arrays including direct SnAgCu to Cu contacts at their bottom bumps was investigated. Based on the resulting increase in the IMC thickness the average mass flux of Cu and Sn were calculated. The activation energies (EA ) diffusion constants (D0 ), effective charges (Z*) and heats of transport (Q*) are determined by measurement. With these parameters the mass fluxes due to concentration gradients, electromigration and thermomigration are calculated and the results were implemented in a routine for the dynamical calculation of the IMC-growth. Finally these calculations were validated by measurements. Highlights: Simulation of stress tests on SnAgCu bumps on Cu contact pads Investigation of the CuSn and Cu6 Sn5 formation Material parameters for the modeling of the electromigration and thermomigration driven Cu3 Sn and Cu6 Sn5 formation