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One of the present trends in microelectronic is the embedding of electronic devices directly into structural components. This integration of smart systems into hybrid and light weight structures also is a main objective of MERGE, the research cluster of excellence on Technologies for Multifunctional Lightweight Structures. The integrated silicon sensor system, also called stress monitor chip system...
This paper presents a systematic study of sintered silver. In order to investigate the correlation between processing conditions, microstructures, thermal and electrical properties, sintered silver samples have been prepared in 27 variations of sintering temperature between 200°C and 270°C and sintering pressure between 5 MPa and 25 MPa. For the thermal and electrical characterization, the innovative...
The steady state method is a commonly used and in principle simple way to measure thermal resistance and conductivity of thermal interface materials (TIMs). The sample must be positioned between a hot and a cold plate with constant temperatures, whereby a heat flow through the sample and temperature gradient across the sample are generated. To determine the thermal resistance of the sample the heat...
In this paper, an accelerated and cost-effective characterization method for bi-material interfaces under cyclic loading using a Miniaturized Cyclic Mixed-mode Bending (MCMB) test setup is presented. The Modified Single Leg Bending (MSLB) samples are acquired directly from production-line Thin Quad Flat Package (TQFP) which provide a mixed-mode I + II loading condition. Under sub-critical cyclic loading,...
The steady state method is a commonly used and in principle simple way to measure thermal resistance and conductivity of thermal interface materials (TIMs). A heat flow through the TIM has to be generated and the temperature gradient across the TIM has to be measured. This is also defined by the ASTM standard ASTM D5470 [4]. To generate the heat flow the TIM must be positioned between a hot and a...
In automotive electronics, complex automotive functionalities are managed by car's computers such as electronic control units (ECU). Albeit extremely rare, accidental drop impacts may occur during transportation or mounting ECUs on automobiles, damaging the built-in printed circuit board (PCB)/ball grid array (BGA) package assembly. However, due to larger package dimensions together with heavy components...
The strength of poly-silicon membranes was investigated by experimental tests and numerical simulations. A new fracture test has been developed that replicates the loading situation under real service conditions well but with higher stress level. A set of 45 membranes was tested at each of the three positions on the wafer in order to assure statistical accuracy and to evaluate the strength distribution...
The ongoing development towards increasing functional density and performance drives the improvement of IC packaging and interconnection technologies. However, new integration technologies, such as through silicon vias (TSVs) for 3D stacking for heterogeneous systems as well as rigid micro-bumps together with the utilization of delicate new (porous ultra low-k) materials weaken the mechanical stability...
A parametric transient thermo-electrical coupled PSPICE macro model for a power cable as well as the verification results of the experimental and finite element simulation will be introduced. The paper describes the modeling and simulation of a simplified, single-core cable parametric model, for the use in a circuit simulator e.g. PSPICE. The verification of the simulation data between ANSYS and PSPICE...
Commonly computational methods are used to determine and enhance the lifetime of electronics and electronic systems. The validity of such methods highly depends on the used material data and therefore on the quality of the accompanying experiments. For this reason different methods were combined to better determine the thermal state of a desired device of variable size, while providing this data within...
The paper presents a new stress measurement method on base of stress relief caused by local material removal with ion milling in FIB equipment. Stress relief deformations extracted from SEM micrographs by means of digital image correlation allow the determination of stresses, as well as to estimate Young's modulus on the position of ion milling. The paper gives an introduction into the method. The...
More and more functionalities will soon be integrated into lightweight structures made of fiber reinforced polymers (FRP). This combines very different materials in minimum space. Consequently, thermo-mechanical risks are of vital concern. The complex stress situation requires a systematic and scalable toolbox of methodologies capable of keeping pace with the growing number and diversity in possible...
In this paper we examine the influence of different characteristics of TQFP (thin quad flat package) components on package behavior by simulation and experiment. The varied parameters are the package dimensions, rate-dependent material properties such as viscoelasticity and cure shrinkage and external boundary conditions.
Micro and nano functional systems like MEMS and smart systems are exposed to complex and very challenging service conditions (e.g., within airframe structures or in automotive applications under the hood or within battery cells). Therefore, long-term reliability and structural integrity of the chassis and the printed wiring boards is of rising concern. These parts are often made of fiber reinforced...
The ongoing development of highly integrated electronic packages leads to a steadily increasing number of material interfaces within a package. In combination with increasing harshness (vibration, humidity, temperature) of the system environment the reliability of such systems is often dominated by interface fracture. Therefore interface fracture mechanics is one of the main focuses of electronics...
This paper introduces a miniaturized frictionless fan concept, which is similar to a piezo-electric driven fan principle and that can fits into a size of a matchbox. This type of fan has been employed for the enhancement of heat transfer by increasing the fluid circulation in regions which are otherwise stagnant. The introduced fan is based on a flexible blade whose vibration is driven by means of...
The application of copper-TSVs for 3D-IC-integration generates novel challenges for reliability analysis and prediction, i.e. to master multiple failure criteria for combined loading including residual stresses, interface delamination, cracking and fatigue. So, the thermal expansion mismatch between copper and silicon yields to stress situation in silicon surrounding the TSVs which is influencing...
The paper presents a new measurement method for residual stresses introduced by manufacturing in BEoL structures. Material removal by FIB ion milling is used to release elastically frozen stresses. Normal stress components are calculated from local stress relaxation nearby milled trenches. A validation of the new technique is accomplished by additional bow measurements on defined layers on substrate...
Miniaturization and increasing functional integration push the development of feature sizes of advanced CMOS down to the nanometer range. New low-k and ultra low-k materials in Back-end of line (BEoL) structures cause new challenges for reliability analysis and prediction, in addition. A combined numerical/experimental approach will be explained towards optimizing fracture and fatigue resistance of...
fibDAC stress relief is a new method developed to measure stresses on micro and nanotechnology devices. The classical macroscopic technique of stress relief by material removal has been adopted to determine stress with very high spatial resolution and marginal restrictions regarding the material under test. Focused Ion Beam (FIB) milling is used to remove locally material. Cross correlation algorithms...
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