Thermal cycling is widely used as a qualification test in the microelectronic industry. This paper investigates an intriguing failure mode observed in such a test. Near the corners of a silicon die, shear stresses arise due to thermal expansion mismatch between the silicon and the packaging substrate. These shear stresses may have a small magnitude, being transmitted through packaging polymers,...

This paper investigates the effects of thin plastically deformable layers embedded in an elastic coating upon debonding of a multilayer from its substrate. Such coatings are normally deposited at high temperature and cooled to ambient, resulting in significant stresses from thermal expansion mismatch. Other stresses can develop during subsequent thermal cycling if volumetric changes such as pha...

Transition theory has been used to derive the elasticplastic and transitional stresses. Results obtained have been discussed numerically and depicted graphically. It is observed that the rotating disk made of incompressible material with inclusion require higher angular speed to yield at the internal surface as compared to disk made of compressible material. It is seen that the radial and circu...

Evidence has accumulated recently that a high-capacity electrode of a lithium-ion battery may not recover its initial shape after a cycle of charge and discharge. Such a plastic behavior is studied here by formulating a theory that couples large amounts of lithiation and deformation. The homogeneous lithiation and deformation in a small element of an electrode under stresses is analyzed within ...

Background: An electronic device consists of electronic components attached on a circuit board. Reliability of such a device is limited to fatigue properties of the components as well as of the board. Printed circuit board (PCB) consists of conducting traces and vertical interconnect access (via) out of copper embedded in a composite material. Usually the composite material is fiber reinforced ...

Grit blasting is a surface plastic deformation technique aimed to increase the surface area available for bone/implant apposition, which contributes to improve fixation and mechanical stability of Ti-6Al-4V implants. Besides roughening, grit blasting also causes surface contamination with embedded grit particles and subtle subsurface microstructural changes that, although does not challenge the...

Nucleation and interface propagation criteria are derived with account for temperature variation in the course of phase transition (PT) and internal variables. A model problem concerning the nucleation of thin inclined infinite layer in a rigid-plastic half-space under prescribed normal and shear stresses is solved. Nontrivial effect of shear stress on the PT pressure is shown.

Tibial component loosening is an important failure mode in unicompartmental knee arthroplasty (UKA) which may be due to the 6-8 mm of bone resection required. To address component loosening and fixation, a new early intervention (EI) design is proposed which reverses the traditional material scheme between femoral and tibial components. The EI design consists of a plastic inlay for the distal f...

Plastic injection molding is discontinuous and a complicated process involving the interaction of several variables for control the quality of the molded parts. The goal of this research was to investigate the optimal parameter selection, the significant parameters, and the effect of the injection-molding parameters during the post-filling stage (packing pressure, packing time, mold temperature...

in this paper, an analytical solution for computing the linear plastic stresses and critical temperature and pressure in a fgm hollow cylinder under the internal pressure and temperature is developed. it has been assumed that the modulus of elasticity and thermal coefficient of expansion were varying through thickness of the fgm material according to a power law relationship. the poisson's...