Area of contact and thermal transport across transfer-printed metal-dielectric interfaces

Abstract

Recent experiments suggest that the interfacial thermal conductance of transfer printed metal-dielectric interfaces is ∼45 MW/m2K at 300 K, approaching that of interfaces formed using physical vapor deposition. We investigate this anomalous result using a combination of theoretical deformation mechanics and nanoscale thermal transport. Our analysis shows that plastic deformation and capillary forces lead to significantly large fractional areal coverage of ∼0.25. The conductance predicted from theory is on the same order of magnitude (∼18 MW/m2K) as the experimental data and partially explains the temperature trend. There remains a quantitative discrepancy between data and theory that is not explained through deformation of the asperities alone. We suggest that capillary bridges formed in the small asperities contribute significantly to heat conduction. A preliminary analysis shows this to be plausible based on available data. This work shows that metallic interconnects formed using transfer printing are not at a disadvantage compared to ones formed using vapor deposition, in terms of heat flow characteristics.

Thermal conductance across β-Ga2O3-diamond van der Waals heterogeneous interfaces

“…The van der Waals bonding at Ga2O3-diamond interface is much weaker than covalent bonds, which reduces TBC significantly. 17,20,[29][30] The calculated results shed light on the possible TBC with perfect interface, which guide the material growth and device design. To understand the impact of the Ga2O3-substrate TBC on the thermal performance of a power device, we use an analytical solution for the temperature rise in multilayer structures with (a) (b) discrete heat sources.…”

“…The TBC of mechanically joined materials could be as low as 0.1 MW/m 2 -K while the interfacial thermal conductance of transfer-printed metal films is in the range of 10-40 MW/m 2 -K. [15][16][17][18][19] Thermal transport across Van der Waals interfaces is limited by the real contact area and low phonon transmission due to weak adhesion energy even if there exists the possibility to achieve a high TBC. [20][21][22] Thermal transport across these interfaces remains an open issue due to the limited amount of experimental data available in the literature. Therefore, it is of great significance to study the thermal conductance across Ga2O3-diamond interfaces for both real-world power electronics applications and fundamental thermal science of heat transport across Van der Waals interfaces.…”

Morse potential-based model for contacting composite rough surfaces: Application to self-assembled monolayer junctions

“…where the corresponding interaction energy per unit area is 41 4.712 Â 10 10 N/m 2 (Poisson ration) 41 0.44 H (hardness) 42 210 MPa Asperity properties…”

“…(B4)], which is consistent with those reported in literature for sputtered gold. 41 The adhesive pressure between the flat gold substrate and each of the three components in the asperities and the contact pressure are plotted in Fig. 5(c) as a function of the mean separation between the two surfaces.…”

“…We follow the methodology described by Seong et al 41 and Prasher and Phelan 89 to obtain the area-corrected prediction of interface thermal conductance G int M=LJ using…”