Characterization of interfacial thermal resistance by acoustic micrography imaging

Haque, S.; Lü, Gongxuan; Goings, J.; Sigmund, J.

doi:10.1016/s0026-2714(99)00239-5

Cited by 15 publications

(8 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This approximation, however, poses a problem from a theoretical point of view because the length scale of inhomogeneity in high‐resolution models is comparable to the widths of Fresnel zones (Passier & Snieder 1995). Other domains where scattering is considered to be important are ocean acoustics (Kuperman et al 1998), medical imaging (Baba et al 1989; King & Shao 1990) and non‐destructive testing experiments (Haque et al 1999).…”

Section: Introductionmentioning

confidence: 99%

The effect of small-scale heterogeneity on the arrival time of waves

Spetzler

Snieder

2001

Geophysical Journal International

View full text Add to dashboard Cite

Summary Small‐scale heterogeneity alters the arrival times of waves in a way that cannot by explained by ray theory. This is because ray theory is a high‐frequency approximation that does not take the finite frequency of wavefields into account. We present a theory based on the first‐order Rytov approximation that predicts well the arrival times of waves propagating in media with small‐scale inhomogeneity with a length scale smaller than the width of Fresnel zones. In the regime for which scattering theory is relevant we find that caustics are easily generated in wavefields, but this does not influence the good prediction of finite frequency arrival times of waves by scattering theory. The regime of scattering theory is relevant when the characteristic length of heterogeneity is smaller than the width of Fresnel zones. The regime of triplications is independent of frequency but it is more significant the greater the magnitude of slowness fluctuations.

show abstract

Section: Introductionmentioning

confidence: 99%

The effect of small-scale heterogeneity on the arrival time of waves

Spetzler

Snieder

2001

Geophysical Journal International

View full text Add to dashboard Cite

show abstract

“…Non-destructive testing consisted of X-Ray imaging [212] and Scanning Acoustic Microscopy (SAM) [213], Destructive testing was undertaken using precision grinding [214], coupled with high-power microscopy for imaging of exposed section planes. This combined approach serves to eliminate potential modelling uncertainties associated with possible deviation from nominal component design.…”

Section: Component Structural Analysismentioning

confidence: 99%

An Experimental Assessment of Computational Fluid Dynamics Predictive Accuracy for Electronic Component Operational Temperature

Eveloy¹,

Rodgers²,

Hashmi

2003

Heat Transfer: Volume 3

View full text Add to dashboard Cite

The flow modeling approaches employed in Computational Fluid Dynamics (CFD) codes dedicated to the thermal analysis of electronic equipment are generally not specific for the analysis of forced airflows over populated Printed Circuit Boards. This limitation has been previously highlighted [1], with component junction temperature prediction errors of up to 35% reported. This study evaluates the predictive capability of candidate turbulence models more suited to the analysis of electronic component heat transfer. Significant improvements in component junction temperature prediction accuracy are obtained, relative to a standard high-Reynolds number k-e model, which are attributed to better prediction of both board leading edge heat transfer and component thermal interaction. Such improvements would enable parametric analysis of product thermal performance to be undertaken with greater confidence in the thermal design process, and the generation of more accurate temperature boundary conditions for use in Physics-of-Failure based reliability prediction methods. The case is made for vendors of CFD codes dedicated to the thermal analysis of electronics to consider the adoption of eddy viscosity turbulence models more suited to board-level analysis.

show abstract

“…Many techniques, such as C-Mode Scanning Acoustic Microscopy (CSAM) [5,6], radiography [7], infrared microscopy [7], scanning electron microscopy [8], and transient thermal tomography [9], have been employed in an effort to characterize the physical integrity of TIM bond layers while under stress, or after being stressed.…”

Section: Introductionmentioning

confidence: 99%

Capacitive sensing of local bond layer thickness and coverage in thermal interface materials

Taylor

Garimella

2016

International Journal of Heat and Mass Transfer

View full text Add to dashboard Cite

An instrumentation technique is developed using embedded capacitive sensors to measure the thickness and evenness of coverage of a thin layer of dielectric thermal interface material (TIM) between two substrates. The technique requires an array of sensors embedded into one substrate, with an electrically conductive opposing substrate. Local capacitance measurements are sensitive to both local bond layer thickness and local voiding. We propose a means for using an array of capacitance measurements to interpret both bond layer thickness and local voiding at every sensor location. An algorithm is developed which reveals both characteristics from a single set of capacitance measurements. Experiments are conducted with thermal grease layers of different bond layer thicknesses and void distributions using a prototype system constructed on printed circuit boards. The thickness and void distribution are successfully mapped across the bond layer using the algorithm developed. The technique offers a sensing approach for in situ instrumentation of layers of thermal grease in a thermal test vehicle.

show abstract

Characterization of interfacial thermal resistance by acoustic micrography imaging

Cited by 15 publications

References 4 publications

The effect of small-scale heterogeneity on the arrival time of waves

The effect of small-scale heterogeneity on the arrival time of waves

An Experimental Assessment of Computational Fluid Dynamics Predictive Accuracy for Electronic Component Operational Temperature

Capacitive sensing of local bond layer thickness and coverage in thermal interface materials

Contact Info

Product

Resources

About