Articles techniques et présentations

Since a couple of years, sintering becomes more and more important for power electronics. To press a semiconductor under high temperature in silver paste on a substrate promises benefits for durability. Tests with semiconductors of different thickness expose some problems. After the cool ... En savoir plus

Rotaxanes are a class of molecules recently developed in laboratory that have been heralded as possible molecular motors. The motor is constituted by a linear molecule (thread) and a ring-shaped molecule (macrocycle), which is free to move along the thread, switching between two, or ... En savoir plus

The current paper focuses on the creation of a consistent environment for the numerical prediction of the physical properties of polymer composite. A limitation factor for the successful simulation of composite processes is the correct estimation of the effective properties depending on ... En savoir plus

Large deflection actuators are becoming increasingly important for microsystems. Since actuation forces are usually small, large deflection actuators usually require flexures with low stiffness. Rectangular serpentine flexures are often used for such actuators due to their low stiffness ... En savoir plus

New giant piezoelectric factor materials such as PMN-PT and PZN-PT were researched during the last decade and are actually becoming commercially available. As they seem very attractive for actuator designs, we studied their potential in replacing PZT ceramics. In a first comparative ... En savoir plus

A small particle or a nano-sized object placed in a liquid is subject to random collisions with solvent molecules. The resulting erratic movement of the object is known as Brownian motion, which, in nature, cannot be used to any practical advantage both in natural systems (such as ... En savoir plus

Outline of presentation: theory of phase-field modeling of ferroelectric materials parameter identification in free energy density finite element implementation: PDE form weak form periodic boundary conditions: electrical mechanical domain configurations intrinsic and extrinsic ... En savoir plus

The oxidation behavior of metallic nanoparticles is investigated in respect to material parameters like Mott potential, defects on the microstructure and oxide volume increase per ionic defect. An emphasis is laid on magnetic nanoparticles where the degree of oxidation can be measured ... En savoir plus

Flip-chip interconnection technologies have been tested through the use of a test chip with embedded single-bump daisy chains. The Flip-Chip technologies are selected among Au bump Thermocompression (TC) with and without Nonconductive Adhesives (NCA) underfiller, anisotropic conductive ... En savoir plus

Capacitor Discharge Sintering (CDS) is an ultrafast Electric Current Assisted Sintering method (u-ECAS) suited for electrically conductive powders. It is characterized by relatively short processing times (milliseconds range) and much lower sintering temperatures than the melting point ... En savoir plus