Thermo-mechanical reliability evaluation of thin electronic packages with high density interconnects

Abstract

The trend of electronic packages which comprises electronic devices can be described by two major words, “Miniaturization” and “Diversification”. That is, electronic packages have become thinner and showed higher performance than before to meet consumer demand. It can be achieved by the development of various packaging technologies. One of them is flip-chip packaging technology, and another is 3-dimensional packaging technology. Through these technologies, increase the intensity of integrated circuit in a limited area or volume, and realize high electrical performance by reducing electrical path length.All electronic packages experienced thermally induced strain or stress due to mismatches of the coefficient of thermal expansion (CTE) among component materials under their service conditions or environmental temperature variation. The thermally induced deformation can be categorized by two parts, one is global deformation due to CTE mismatch between the chip and the substrate, and the other is local deformation because of the CTE mismatch between the adjacent materials at the interfaces. Excessive global deformation, so called warpage, causes various reliability problems. Furthermore, it is known that failure of electronic packaging is related to the local strain concentration at corners and interfaces among heterogeneous materials related to local deformation. Therefore, it is essential to investigate the deformation behavior, and strain (or stress) distribution of not only overall packages but also high density interconnects in packages for their thermo-mechanical reliability evaluation.In this dissertation, thermo-mechanical reliability of thin electronic packages with high density interconnects (HDIs), such as thin and flexible packages with anisotropic conductive film (ACF) interconnect, and a stack package with through-silicon via (TSV) and solder/non-conductive film (NCF) hybrid interconnects was evaluated.For observing residual warpage of thin packages,...