Shear-Induced Crystallization at Polymer–Substrate Interface: The Slippage Hypothesis

2011 ◽  
Vol 44 (17) ◽  
pp. 6919-6927 ◽  
Author(s):  
Bo Shen ◽  
Yongri Liang ◽  
Chenggui Zhang ◽  
Charles C. Han
2021 ◽  
Author(s):  
J. K. Wenderott ◽  
Ban Xuan Dong ◽  
Jojo A. Amonoo ◽  
Peter F. Green

2020 ◽  
Vol 22 (37) ◽  
pp. 21297-21306
Author(s):  
Min Wang ◽  
Jiapeng Zhang ◽  
Shenglin Zhou ◽  
Zhaohui Yang ◽  
Xiaohua Zhang

The influence of the coexistence of a free surface and a polymer–substrate interface on the glass transition behaviour of polymer chains on CNT sidewalls.


1989 ◽  
Vol 154 ◽  
Author(s):  
I. U. Kim ◽  
P. R. Troyk ◽  
J. E. Anderson

AbstractSilicone resins and gels have been used extensively for IC protection. Reduction of interfacial moisture and ionic contamination is considered crucial to device reliability.The present research has revealed an interesting phenomenon. Prolonged lifetime was obtained for comb pattern samples using a non-conventional encapsulation method. In order to increase specimen sensitivity to interfacial moisture, samples were contaminated prior to encapsulation. Three groups of contaminated samples encapsulated with polysiloxane were produced. Group I was encapsulated with a polymer/CaCl2/polymer/substrate structure. The structure of group II consisted of only the polymer on the contaminated substrates. Group III was encapsulated with a CaCl2 embedded polymer/polymer /substrate structure. Following exposure at 85°C, 100−10 amperes after 2,000 hrs, with no visible corrosion. Group II and III samples showed visible corrosipn after 390 to 470 hrs with leakage current of the order of 10−5 amperes. Direct measurement of RH at the polymer/substrate interface and water sorption experiments were done to explain the mechanisms of these packaging structures.The experimental results suggest that a desiccating multilayer coating can maintain low interfacial water concentrations. During exposure to high external RH, water from the surroundings diffuses through the top layer, producing an interlayer consisting of a solid CaCl2 and a CaCl2-saturated solution. Until all of the salt dissolves, the water chemical potential of the saturated solution defines the water content at the polymer/substrate interface. Hence the RH at the polymer/substrate interface was maintained below that required to dissolve the residual surface contamination for a longer time than by conventional encapsulation. This technique could be useful to reduce the dependence of IC reliability upon pre-encapsulation cleaning.


2012 ◽  
Vol 45 (17) ◽  
pp. 7098-7106 ◽  
Author(s):  
M. Asada ◽  
N. Jiang ◽  
L. Sendogdular ◽  
P. Gin ◽  
Y. Wang ◽  
...  

2003 ◽  
Vol 779 ◽  
Author(s):  
T. John Balk ◽  
Gerhard Dehm ◽  
Eduard Arzt

AbstractWhen confronted by severe geometric constraints, dislocations may respond in unforeseen ways. One example of such unexpected behavior is parallel glide in unpassivated, ultrathin (200 nm and thinner) metal films. This involves the glide of dislocations parallel to and very near the film/substrate interface, following their emission from grain boundaries. In situ transmission electron microscopy reveals that this mechanism dominates the thermomechanical behavior of ultrathin, unpassivated copper films. However, according to Schmid's law, the biaxial film stress that evolves during thermal cycling does not generate a resolved shear stress parallel to the film/substrate interface and therefore should not drive such motion. Instead, it is proposed that the observed dislocations are generated as a result of atomic diffusion into the grain boundaries. This provides experimental support for the constrained diffusional creep model of Gao et al.[1], in which they described the diffusional exchange of atoms between the unpassivated film surface and grain boundaries at high temperatures, a process that can locally relax the film stress near those boundaries. In the grains where it is observed, parallel glide can account for the plastic strain generated within a film during thermal cycling. One feature of this mechanism at the nanoscale is that, as grain size decreases, eventually a single dislocation suffices to mediate plasticity in an entire grain during thermal cycling. Parallel glide is a new example of the interactions between dislocations and the surface/interface, which are likely to increase in importance during the persistent miniaturization of thin film geometries.


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