Analytical calculation method of effect of interconnect layer damage on power cycling lifetime. (September 2019)

• Record Type: Journal Article
• Authors: Sato, Y.; Yamazaki, K.; Uchida, Y.; Sakai, N.; Ito, Y.; Kobayashi, H.; Soda, S.; Nishikawa, K.
• Is Part Of: Microelectronics and reliability. Volume 100/101(2019)
• Publication Date: 2019-09
• Subjects: 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.2019.06.068
• Languages: English
• ISSNs: 0026-2714

Abstract

Abstract: We developed a prediction method of power cycling (PC) lifetime affected by the cracks in the interconnect solder layer between the insulating substrate and the baseplate (the baseplate solder layer) in power modules. The baseplate solder layer sustains damage mainly during PC tests due to the recent improvement in the reliability of die-attach materials and the junctions between the chips and connecting wire. In this paper, we investigated a method that predicts the effect of cracks in the baseplate solder layer on the PC test. Cracks increase the thermal resistance and module temperature, both of which are key parameters of PC lifetime. Therefore, it is possible to calculate the lifetime using empirical equations of these parameters. We performed a PC test and verified that its calculation and result agree with high precision. We also discuss the relationship between the vertical cracks and PC lifetime in detail. Highlights: A degree of cracks occurred during power cycling test is calculated from equations. The effect of cracks on junction temperature is represented to equations. Cracks occur perpendicular to a solder layer of modules during power cycling test. The degree of cracks is quantified by a binary process for SEM images. The calculation values coincide with power cycling test results with a high accuracy.