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Interfacial failure under thermal cycling conditions is one of the main concerns in package design, To minimize such failure in multi-layered electronic assemblies and packages, it is important to develop a better understanding of the reliability at a molecular level. In this paper, molecular dynamics (MD) simulations were conducted to investigate the interfacial energy of the epoxy molding compound (EMC) cuprous oxide system during the thermal cycling test. In order to investigate the effect of the cuprous oxide content in the copper substrate on the interfacial adhesion, two kinds of MD models were examined in this study. The results revealed that the cuprous oxide content in the copper substrate had a large effect on the interfacial adhesion between the EMC and copper, which is consistent with the experimental observation. [DOI: 10.1115/1.2429707] Keywords: delamination, thermal cycling, molecular dynamics, cuprous oxide content, interfacial adhesion

Conductive polymer composites were prepared by sintering a mixture of ultra-high molecular weight polyethylene (UHMWPE) powder and carbon black. Two processing parameters - time and temperature - were shown to have a notable effect on the resistivity of the composites. The relationships between the processing parameters and morphology were studied using optical microscopy and transmission electron microscopy (TEM). The results of the optical microscopy studies indicate that the carbon black is distributed in the interfacial regions between the UHMWPE particles. The dimension of the carbon black channels increases with the carbon black concentration. TEM micrographs show that a high degree of intermixing between the carbon black and the polymer occurs at higher temperatures and longer processing times, resulting in higher resistivities. A positive temperature coefficient (PTC) effect was observed for these materials. A mechanism for the PTC effect in this system is proposed. The magnitude of the PTC effect is found to be inversely proportional to the dimension of the carbon black channels in the composites. The dimension is directly related to the carbon black concentration. The PTC effect is a result of the polymer volume expansion caused by melting of the crystallites. A large PTC effect is observed for the composites with a low carbon black concentration and vice versa. No negative temperature effect (NTC) is observed at temperatures substantially above the melting point of the polymer., INTRODUCTION Conductive polymer composite materials have a wide range of industrial applications - they are used in antistactic materials, self-regulating heaters (1, 2), over-current and over-temperature protection devices (3, 4) [...]

A study was conducted to examine the molecular dynamics simulations of interfacial thermal conductance between a functionalized single-wall carbon nanotube and a silicon substrate. Findings suggested that the interfacial thermal conductance increased with the increase in the number of chemical bonds formed between the carbon nanotube and the substrate.