Study of fatigue failure in Al-chip-metallization during power cycling. (April 2015)

• Record Type: Journal Article
• Authors: Durand, C.; Klingler, M.; Coutellier, D.; Naceur, H.
• Is Part Of: Engineering fracture mechanics. Volume 138(2015)
• Page Start: 127
• Page End: 145
• Publication Date: 2015-04
• Subjects: Crack growth -- Finite-elements-methods (FEM) simulations -- MOSFET -- Power cycling -- Chip-metallization -- Thermomechanics; Fracture mechanics -- Periodicals; Rupture, Mécanique de la -- Périodiques; Fracture mechanics; Periodicals; 620.112605
• DOI: 10.1016/j.engfracmech.2015.02.020
• Languages: English
• ISSNs: 0013-7944

Abstract

Highlights: The Al metallization power cycling behavior of a module with Cu clip is studied. Degradations and plastic strain occur at the area beneath the top solder meniscus. A crack in Al with a Crack Tip Opening Displacement fracture criterion is simulated. Crack growth occurs along the local mode 2 direction. Low T jmin, large Δ T j and short t on are critical for plastic strain and crack growth. Abstract: This paper studies the failure mechanisms occurring in the chip-metallization of a new power module using a copper clip soldered on the top side of the chip, instead of aluminum wire bonds. Both power cycling tests and thermo-mechanical Finite Elements simulations are performed. Simulations of electronic packages is really advantageous: power cycling tests are time consuming and ageing parameters difficult to monitor, whereas simulations allow a detailed study of stresses, plastic strain and even crack growth. A numerical sensitivity study, previously unseen, gives us important information about the influence of test parameters on the mechanical behavior of chip-metallization.