The Experts below are selected from a list of 627 Experts worldwide ranked by ideXlab platform

V.g. Karpov - One of the best experts on this subject based on the ideXlab platform.

  • Metal Whisker growth induced by localized high intensity dc electric fields
    MRS Advances, 2018
    Co-Authors: Vamsi Borra, V.g. Karpov, Osama Oudat, Daniel G Georgiev, Diana Shvydka
    Abstract:

    In this work, a very high, locally applied electric field was used to induce Whisker nucleation on an Sn film. The field was generated by using a conductive AFM tip and applying a voltage bias between the sample and the conductive cantilever. The tip-sample separation distance was thus controllable, and any dielectric breakdown could be avoided. At locations where the AFM tip was positioned for an extended period, minuscule Whiskers were observed, whose growth direction matched vertical orientation of the field.

  • The probabilistic distribution of Metal Whisker lengths
    Journal of Applied Physics, 2015
    Co-Authors: D. Niraula, V.g. Karpov
    Abstract:

    Significant reliability concerns in multiple industries are related to Metal Whiskers, which are random high aspect ratio filaments growing on Metal surfaces and causing shorts in electronic packages. We derive a closed form expression for the probabilistic distribution of Metal Whisker lengths. Our consideration is based on the electrostatictheory of Metal Whiskers, according to which Whisker growth is interrupted when its tip enters a random local “dead region” of a weak electric field. Here, we use the approximation neglecting the possibility of thermally activated escapes from the “dead regions,” which is later justified. We predict a one-parameter distribution with a peak at a length that depends on the Metal surface charge density and surface tension. In the intermediate range, it fits well the log-normal distribution used in the experimental studies, although it decays more rapidly in the range of very long Whiskers. In addition, our theory quantitatively explains how the typical Whisker concentration is much lower than that of surface grains. Finally, it predicts the stop-and-go phenomenon for some of the Whiskers growth.

Antonios Zavaliangos - One of the best experts on this subject based on the ideXlab platform.

  • driving force and mechanism for spontaneous Metal Whisker formation
    Physical Review Letters, 2004
    Co-Authors: Michel W Barsoum, E N Hoffman, R D Doherty, S Gupta, Antonios Zavaliangos
    Abstract:

    The room temperature spontaneous growth of low melting point Metal Whiskers, such as Sn, poses a serious reliability problem in the semiconducting industry; a problem that has become acute with the introduction of Pb-free technology. To date, this 50+ year old problem has resisted interpretation. Herein we show that the driving force is essentially a reaction between oxygen and the sprouting Metal. The resulting volume expansion creates a compressive stress that pushes the Whiskers up. The model proposed explains our observations on In and Sn Whiskers and many past observations. The solution is in principle simple: diffusion of oxygen into the Metal must be prevented or slowed down. This was demonstrated by coating the active surfaces with a polymer coating.

Jay Usse - One of the best experts on this subject based on the ideXlab platform.

D. Niraula - One of the best experts on this subject based on the ideXlab platform.

  • The probabilistic distribution of Metal Whisker lengths
    Journal of Applied Physics, 2015
    Co-Authors: D. Niraula, V.g. Karpov
    Abstract:

    Significant reliability concerns in multiple industries are related to Metal Whiskers, which are random high aspect ratio filaments growing on Metal surfaces and causing shorts in electronic packages. We derive a closed form expression for the probabilistic distribution of Metal Whisker lengths. Our consideration is based on the electrostatictheory of Metal Whiskers, according to which Whisker growth is interrupted when its tip enters a random local “dead region” of a weak electric field. Here, we use the approximation neglecting the possibility of thermally activated escapes from the “dead regions,” which is later justified. We predict a one-parameter distribution with a peak at a length that depends on the Metal surface charge density and surface tension. In the intermediate range, it fits well the log-normal distribution used in the experimental studies, although it decays more rapidly in the range of very long Whiskers. In addition, our theory quantitatively explains how the typical Whisker concentration is much lower than that of surface grains. Finally, it predicts the stop-and-go phenomenon for some of the Whiskers growth.

Michel W Barsoum - One of the best experts on this subject based on the ideXlab platform.

  • driving force and mechanism for spontaneous Metal Whisker formation
    Physical Review Letters, 2004
    Co-Authors: Michel W Barsoum, E N Hoffman, R D Doherty, S Gupta, Antonios Zavaliangos
    Abstract:

    The room temperature spontaneous growth of low melting point Metal Whiskers, such as Sn, poses a serious reliability problem in the semiconducting industry; a problem that has become acute with the introduction of Pb-free technology. To date, this 50+ year old problem has resisted interpretation. Herein we show that the driving force is essentially a reaction between oxygen and the sprouting Metal. The resulting volume expansion creates a compressive stress that pushes the Whiskers up. The model proposed explains our observations on In and Sn Whiskers and many past observations. The solution is in principle simple: diffusion of oxygen into the Metal must be prevented or slowed down. This was demonstrated by coating the active surfaces with a polymer coating.