The Effects of Environment and Fatigue on the Adhesion and Subcritical Debonding of Dielectric Polymers

1999 ◽  
Vol 565 ◽  
Author(s):  
J. M. Snodgrass ◽  
D. Pantelidis ◽  
J. C. Bravman ◽  
R. H. Dauskardt

AbstractThe adhesion of thin film polymers will be critical in the integration of low-κ materials into microelectronic processing. This study describes the adhesion of two promising low-κ polymers (polyimide and benzocyclobutene) to a silicon dioxide surface. Critical adhesion values were measured using interface fracture mechanics samples in a double cantilever beam geometry. The effect of subcritical (time-dependent) delamination was also evaluated for these systems. Subcritical debonding data are important in understanding the effect of environment and temperature on interface reliability. To that end, experiments were conducted over a range of humidities to elucidate the effect of moisture on interface delamination. The important effect of the acceleration of debond growth rates due to cyclic loading is also described. In addition, XPS studies are presented to characterize the debond path in these layered systems.

1975 ◽  
Vol 3 (4) ◽  
pp. 215-234 ◽  
Author(s):  
A. L. Browne ◽  
D. Whicker ◽  
S. M. Rohde

Abstract An analysis is presented for the action of individual tire tread elements on polished sections of pavement covered by thin fluid films. Tread element flexibility, wheel slip, and time-dependent loading are incorporated. The effect of the lateral expansion of tread elements on groove closure is also studied.


2021 ◽  
Vol 6 (1) ◽  
pp. 4
Author(s):  
Vladimir Kogan ◽  
Norio Nakagawa

The magnetic field hz of a moving Pearl vortex in a superconducting thin-film in (x,y) plane is studied with the help of the time-dependent London equation. It is found that for a vortex at the origin moving in +x direction, hz(x,y) is suppressed in front of the vortex, x>0, and enhanced behind (x<0). The distribution asymmetry is proportional to the velocity and to the conductivity of normal quasiparticles. The vortex self-energy and the interaction of two moving vortices are evaluated.


1986 ◽  
Vol 95 (1) ◽  
pp. 353-359 ◽  
Author(s):  
R. A. Collins ◽  
S. C. Edwards ◽  
F. J. Johnson ◽  
A. G. Jones ◽  
L. D. McMahon

2000 ◽  
Vol 15 (12) ◽  
pp. 2758-2769 ◽  
Author(s):  
Michael Lane ◽  
Reinhold H. Dauskardt ◽  
Anna Vainchtein ◽  
Huajian Gao

The effects of plasticity in thin copper layers on the interface fracture resistance in thin-film interconnect structures were explored using experiments and multiscale simulations. Particular attention was given to the relationship between the intrinsic work of adhesion, Go, and the measured macroscopic fracture energy, Gc. Specifically, the TaN/SiO2 interface fracture energy was measured in thin-film Cu/TaN/SiO2 structures in which the Cu layer was varied over a wide range of thickness. A continuum/FEM model with cohesive surface elements was employed to calculate the macroscopic fracture energy of the layered structure. Published yield properties together with a plastic flow model for the metal layers were used to predict the plasticity contribution to interface fracture resistance where the film thickness (0.25–2.5 μm) dominated deformation behavior. For thicker metal layers, a transition region was identified in which the plastic deformation and associated plastic energy contributions to Gc were no longer dominated by the film thickness. The effects of other salient interface parameters including peak cohesive stress and Go are explored.


1994 ◽  
Vol 61 (2) ◽  
pp. 471-473 ◽  
Author(s):  
B. Balendran

A compliance model is presented for a DCB specimen for mode-I interface delamination. The undelaminated part of the specimen is modeled by using Reissner’s mixed variational principle from which the rotation of the cross-section at the tip of the crack and the shear stress at the interface are evaluated. The results for a homogeneous beam with midplane crack are deduced and shown to be in better agreement with the experimental and finite element results than any of the existing models.


2010 ◽  
Vol 24 (01n02) ◽  
pp. 164-174 ◽  
Author(s):  
SHANE ZHI YUAN LOO ◽  
PUAY CHENG LEE ◽  
ZAN XUAN LIM ◽  
NATALIA YANTARA ◽  
TONG YAN TEE ◽  
...  

In the current work, a test scheme to evaluate solder joint interface fracture toughness using double cantilever beam (DCB) test has been successfully demonstrated. The obtained results, in terms of critical energy release rate, predict the joint failure based on the principle of fracture mechanics. The results can be used as a materials property in the reliability design of various types of solder-ball joined packages. DCB specimens made of 99.9 wt% copper were selected in the current work. Eutectic Sn -37 Pb and lead-free Sn -3.5 Ag -0.5 Cu solders were used to join two pieces of the copper beams with controlled solder thickness. The test record showed steady propagation of the crack along the solder / copper interface, which verifies the viability of such a testing scheme. Interface fracture toughness for as-joined, extensively-reflowed and thermally aged samples has been measured. Both the reflow treatment and the thermal aging lead to degradation of the solder joint fracture resistance. Reflow treatment was more damaging as it induces much faster interface reaction. Fractographic analysis established that the fracture has a mixed micromechanism of dimple and cleavage. The dimples are formed as a result of the separation between the hard intermetallic compound (IMC) particles and the soft solder material, while the cleavage is formed by the brittle split of the IMCs. When the IMC thickness is increased due to extended interface reaction, the proportion of IMC cleavage failure increases, and this was reflected in the decrease of the critical energy release rate.


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