Adhesion and Reliability of Polymer/Inorganic Interfaces

1998 ◽  
Vol 120 (4) ◽  
pp. 328-335 ◽  
Author(s):  
S.-Y. Kook ◽  
J. M. Snodgrass ◽  
A. Kirtikar ◽  
R. H. Dauskardt
Keyword(s):  
Fracture Resistance ◽  
Strain Energy Release ◽  
Interfacial Fracture ◽  
Fatigue Loading ◽  
Cyclic Fatigue ◽  
Interface Fracture ◽  
Fracture Toughness Test ◽  
Adhesion Promoter ◽  
Polymer Metal ◽  
Microelectronic Components

The reliability of microelectronic components is profoundly influenced by the interfacial fracture resistance (adhesion) and associated progressive debonding behavior. In this study we examine the interfacial fracture properties of representative polymer interfaces commonly found in microelectronic applications. Specifically, interface fracture mechanics techniques are described to characterize adhesion and progressive bebonding behavior of a polymer/metal interface under monotonic and cyclic fatigue loading conditions. Cyclic fatigue debond-growth rates were measured from ~10−11 to 10−6 m/cycle and found to display a power–law dependence on the applied strain energy release rate range, ΔG. Fracture toughness test results show that the interfaces typically exhibit resistance-curve behavior, with a plateau interface fracture resistance, Gss, strongly dependent on the interface morphology and the thickness of the polymer layer. The effect of a chemical adhesion promoter on the fracture energy of a polymer/silicon interface was also characterized. Micromechanisms controlling interfacial adhesion and progressive debonding are discussed in terms of the prevailing deformation mechanisms and related to interface structure and morphology.

The Effect of Fatigue on the Adhesion and Subcritical Debonding of Benzocyclobutene/Silicon Dioxide Interfaces

2000 ◽  
Vol 612 ◽  
Author(s):  
Jeffrey M. Snodgrass ◽  
Reinhold H. Dauskardt
Keyword(s):  
Fatigue Testing ◽  
Strain Energy Release ◽  
Fatigue Loading ◽  
Cyclic Fatigue ◽  
Interface Fracture ◽  
Loading Conditions ◽  
Test Environment ◽  
Adhesion Promoters ◽  
Mechanical Fatigue ◽  
Dielectric Interfaces

AbstractThe effect of fatigue loading on microelectronic thin film interfaces has until now been difficult to quantify. Most industrial fatigue testing uses HAST (Highly Accelerated Stress Testing) protocols, which inherently convolutes the effects of mechanical fatigue and the test environment. Our work focuses on isolating the deleterious effects of mechanical fatigue on interfaces, which we have found to be substantial. In this study, the integrity of a low-k polymer interface involving benzocyclobutene (BCB) and silica was examined under a variety of loading conditions. Critical (fast fracture) adhesion values were measured using standard interface fracture-mechanics geometries. Experiments were then conducted to measure the debond growth rate as a function of the applied strain energy release rate under both static and cyclic loading conditions. Our results show that even under room temperature conditions, debond growth rates measured under cyclic fatigue are considerably faster than those observed under static loading. Results are presented detailing the effects of interface chemistry (adhesion promoters), environmental moisture, and test temperature on the resistance of the interfaces to subcritical debonding. Strategies for increasing resistance of dielectric interfaces to fatigue debonding are outlined.

Adhesion and Progressive Debonding of Polymer/Metal Interfaces: Effects of Temperature and Environment

1999 ◽  
Vol 563 ◽  
Author(s):  
Seung-Yeop Kook ◽  
Amol Kirtikar ◽  
Reinhold H. Dauskardt
Keyword(s):  
Fracture Energy ◽  
Interfacial Fracture ◽  
Fatigue Loading ◽  
Cyclic Fatigue ◽  
Rate Theory ◽  
Metal Interface ◽  
Polymer Metal ◽  
Interfacial Fracture Energy ◽  
Effects Of Temperature ◽  
Novolac Epoxy

AbstractThe interfacial fracture properties of a representative polymer/metal interface commonly found in microelectronic applications are examined. The double cantilever beam (DCB) configuration was used to investigate the effects of environmental variables on interfacial adhesion and progressive delamination under monotonic and cyclic fatigue loading conditions. The steady-state interfacial fracture energy, Gss, taken from the plateau of the R-curve, of a representative silica-filled Phenol-Novolac epoxy on a Nielectroplated Cu substrate showed little sensitivity to the presence of moisture. On the other hand, both the initiation interfacial fracture energy, Gi, and the entire progressive debond curve under fatigue loading were remarkably sensitive to moisture and temperature, respectively. Debonding is modeled in terms of interface structure, chemistry using chemical reaction rate theory, and relaxation process at the debond tip. The activation energy for stage I debond growth is found to be 140 kJ/mol and 63 kJ/mol for stage II for the current polymer/metal interface.

Tailored Nicrostructures to Control Interfacial Toughness

1988 ◽  
Vol 130 ◽  
Author(s):  
T. S. Oh ◽  
R. N. Cannon ◽  
R. O. Ritichie
Keyword(s):  
Fracture Resistance ◽  
Metal Film ◽  
Interfacial Fracture ◽  
Interface Fracture ◽  
Chemical Bonds ◽  
Interfacial Fracture Toughness ◽  
Interfacial Chemistry ◽  
Interfacial Toughness ◽  
Interfacial Fracture Energy ◽  
Metal Interfaces

AbstractFailure of ceramic-metal interfaces in response to residual or applied stress is frequently effectively brittle owing to the propensity for interfacial cracking caused by weaker than average chemical bonds and elastic or plastic discontinuities at the interface. Stronger atomic bonding derived from improved interfacial chemistry can enhance fracture resistance to a degree which may be limited by diversion of the crack into the brittle ceramic.Alternatively, methods under study promote interfacial fracture toughness in glass-Cu bonds via near-interfacial microstructures that encourage greater energy dissipation in a region near the interface fracture. Particular success has obtained from microvoid toughening wherein placement of controlled arrays of microcrack-like-voids in the ductile metal, suitably near the interface, can markedly enhance interfacial fracture energy, e.g. by as much as two orders of magnitude and to much greater toughnesses than for glass. The toughness develops with extension of the crack owing to formation of a bridging zone behind the crack wherein the crack flanks are spanned by ligaments of plastically deforming metal film.

Micromechanics Measurements Applied to Integrated Circuit Microelectronics

1997 ◽  
Vol 473 ◽  
Author(s):  
David R. Clarke
Keyword(s):  
Integrated Circuits ◽  
Integrated Circuit ◽  
Fracture Resistance ◽  
Interface Fracture ◽  
New Techniques ◽  
Fracture Properties ◽  
Engineered Structures ◽  
Mechanical And Fracture Properties ◽  
Interconnect Lines ◽  
Metallic Interconnect

ABSTRACTAs in other engineered structures, fracture occasionally occurs in integrated microelectronic circuits. Fracture can take a number of forms including voiding of metallic interconnect lines, decohesion of interfaces, and stress-induced microcracking of thin films. The characteristic feature that distinguishes such fracture phenomena from similar behaviors in other engineered structures is the length scales involved, typically micron and sub-micron. This length scale necessitates new techniques for measuring mechanical and fracture properties. In this work, we describe non-contact optical techniques for probing strains and a microscopic “decohesion” test for measuring interface fracture resistance in integrated circuits.

New anterior controllable antedisplacement and fusion surgery for cervical ossification of the posterior longitudinal ligament: a biomechanical study

2022 ◽  
pp. 1-9
Keyword(s):  
Fatigue Loading ◽  
Axial Rotation ◽  
Posterior Longitudinal Ligament ◽  
Cyclic Fatigue ◽  
Biomechanical Study ◽  
Biomechanical Stability ◽  
Loading Test ◽  
Crossover Effect ◽  
Flexion Extension

OBJECTIVE The traditional anterior approach for multilevel severe cervical ossification of the posterior longitudinal ligament (OPLL) is demanding and risky. Recently, a novel surgical procedure—anterior controllable antedisplacement and fusion (ACAF)—was introduced by the authors to deal with these problems and achieve better clinical outcomes. However, to the authors’ knowledge, the immediate and long-term biomechanical stability obtained after this procedure has never been evaluated. Therefore, the authors compared the postoperative biomechanical stability of ACAF with those of more traditional approaches: anterior cervical discectomy and fusion (ACDF) and anterior cervical corpectomy and fusion (ACCF). METHODS To determine and assess pre- and postsurgical range of motion (ROM) (2 Nm torque) in flexion-extension, lateral bending, and axial rotation in the cervical spine, the authors collected cervical areas (C1–T1) from 18 cadaveric spines. The cyclic fatigue loading test was set up with a 3-Nm cycled load (2 Hz, 3000 cycles). All samples used in this study were randomly divided into three groups according to surgical procedures: ACDF, ACAF, and ACCF. The spines were tested under the following conditions: 1) intact state flexibility test; 2) postoperative model (ACDF, ACAF, ACCF) flexibility test; 3) cyclic loading (n = 3000); and 4) fatigue model flexibility test. RESULTS After operations were performed on the cadaveric spines, the segmental and total postoperative ROM values in all directions showed significant reductions for all groups. Then, the ROMs tended to increase during the fatigue test. No significant crossover effect was detected between evaluation time and operation method. Therefore, segmental and total ROM change trends were parallel among the three groups. However, the postoperative and fatigue ROMs in the ACCF group tended to be larger in all directions. No significant differences between these ROMs were detected in the ACDF and ACAF groups. CONCLUSIONS This in vitro biomechanical study demonstrated that the biomechanical stability levels for ACAF and ACDF were similar and were both significantly greater than that of ACCF. The clinical superiority of ACAF combined with our current results showed that this procedure is likely to be an acceptable alternative method for multilevel cervical OPLL treatment.

Plasticity contributions to interface adhesion in thin-film interconnect structures

2000 ◽  
Vol 15 (12) ◽  
pp. 2758-2769 ◽  
Author(s):  
Michael Lane ◽  
Reinhold H. Dauskardt ◽  
Anna Vainchtein ◽  
Huajian Gao
Keyword(s):  
Thin Film ◽  
Film Thickness ◽  
Fracture Energy ◽  
Fracture Resistance ◽  
Work Of Adhesion ◽  
Interface Fracture ◽  
Cohesive Stress ◽  
Wide Range ◽  
Macroscopic Fracture ◽  
Metal Layers

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.

Computational simulation of the relaxation of local stresses due to foreign object damage under cyclic loading

2010 ◽  
Vol 224 (2) ◽  
pp. 41-50 ◽  
Author(s):  
T Davis ◽  
J Ding ◽  
W Sun ◽  
S B Leen
Keyword(s):  
Stress Relaxation ◽  
Kinematic Hardening ◽  
Computational Simulation ◽  
Fatigue Loading ◽  
Cyclic Fatigue ◽  
Foreign Object ◽  
Stress Concentrations ◽  
Foreign Object Damage ◽  
Stress Ratios ◽  
The Impact

In this study, the phenomenon of residual stress relaxation from foreign object damage (FOD) is numerically simulated using a hybrid explicit—implicit finite-element method. The effects of cycle fatigue loadings on stress relaxation were studied. FOD is first simulated by firing a 3mm cube impacting onto a plate made of titanium alloy Ti-6Al-4V at 200m/s. The FOD impact produces two distinct stress concentrations: one is compressive directly beneath the impact site; the other is tensile around the outer edge of the impact. The plate was then assumed to be subjected to a cyclic fatigue loading. The stress relaxation was investigated under a range of stress ratios and maximum applied stresses. Two different material models were considered for the simulations, namely an elastic—perfectly plastic model and a non-linear kinematic hardening model.

Fatigue Evaluation in Ceramic Materials by Acoustic Emission

1993 ◽  
Author(s):  
Osama M. Jadaan ◽  
K. C. Liu ◽  
H. Pih
Keyword(s):  
Acoustic Emission ◽  
Count Rate ◽  
Fatigue Loading ◽  
Ceramic Materials ◽  
Cyclic Fatigue ◽  
Fracture Site ◽  
Progressive Damage ◽  
Catastrophic Failure ◽  
Final Fracture ◽  
Fatigue Evaluation

Abstract Progressive damage due to tension-tension cyclic fatigue loading for three distinct ceramic materials was evaluated using the acoustic emission (AE) technique. The objective of this study was to determine the capabilities of the AE method to detect the imminence of failure and to locate potential fracture sites. Results indicated that the AE technique was capable of predicting failure by showing an increase in energy/count rate prior to failure. Although potential fracture sites can be identified, exact location of the final fracture site can be known only when catastrophic failure takes place.

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