Hygro-Thermo-Mechanical Reliability Assessment of a Thermal Interface Material for a Ball Grid Array Package Assembly

The thermal efficacy of thermal interface material (TIM) is highly dependent on its abilit

Innovative off-chip interconnects for 45-nm and sub-45-nm node ICs

Issued as final reportNational Science Foundation (U.S.

Low-cost mixed mode module: Computer-aided mechanical design (MCAD)

Issued as final repor

Development of complaint chip-to-substrate interconnects for sub 32-nm multi-core ICs

Issued as final reportWith the introduction of on-chip low-K dielectric materials, it is increasingly important to reduce on-chip stresses so that the low-K dielectric material will not crack or delaminate. One way to reduce the thermo-mechanical stresses is to introduce compliant structures between the die and the substrate and thus to decouple the die from the substrate. Decoupling the die from the substrate or the substrate from the board by means of mechanically compliant interconnects will reduce stresses created by the coefficient of thermal expansion mismatch. A decoupled diesubstrate or substrate-board interface will allow the different components to expand or contract differently without inducing high stresses in the components. In this work, we report the design, fabrication, modeling, and characterization of innovative multi-path fan-shaped off-chip compliant interconnects. The proposed interconnects can be fabricated at the wafer-level and are cost-effective, can be of fine pitch and scalable, and will have redundant electrical paths.National Science Foundation (U.S.

THERMO-MECHANICAL FATIGUE LIFE ESTIMATION OF ORGANIC BGA PACKAGES USING LASER MOIRE INTERFEROMETRY

ABSTRACT Accelerated Thermal Cycling (ATC) is traditionally used for assessing solder joint reliability. ATC typically takes as long as three to four months to complete. This paper proposes a new method to determine the fatigue life of solder joints using laser moiré technique. The developed method takes about a week to complete and gives us the detailed deformation behavior of each solder ball in the package at various temperatures. The developed method has been demonstrated for a high I/O organic BGA package. To illustrate the efficacy of the method, the results have been validated using experimental thermal cycling data

Modeling and simulation of embedded passives using rational functions in Multi-layered substrates

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