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Stiction is a major failure mode of MEMS as microscopic structures tend to adhere to each other when their surfaces enter into contact. Although increasing the restoring forces of switch devices could overcome the stiction effect, this is not practical, as in turn, it also increases the actuation voltage. Therefore stiction prediction is important to be considered when designing micro- and nano- devices...
A simulation of the Board Level Drop-Test is performed to evaluate some WL-CSP (Wafer-Level Chip-Scale Packages) performances. An elastic-plastic model is applied on both solder bump and copper pad materials. It intends to demonstrate that copper plasticity is mandatory due to the large plastic strain occuring in these materials. A statistical analysis discusses the required accuracy for the modeling...
Since the thickness of the stacked silicon chips in 3D integration has been thinned to less than 100 ??m, the local thermal deformation of the chips has increased drastically because of the decrease of the flexural rigidity of the thinned chips. The clear periodic thermal deformation and thus, the thermal residual stress distribution appear in the stacked chips due to the periodic alignment of metallic...
This paper presents an integrated numerically-driven modelling methodology for the design of miniaturised/integrated (Mintegrated) products and the selection/control of associated manufacturing processes. The focus is on the numerical techniques and methods that underpin several design procedures aiding the embodiment design stage of product development. A design assistant tool is developed as an...
Moisture induced interfacial delamination failures are often found in a microelectronic package within die attach epoxy and laminate substrate during moisture sensitivity reliability test. In this paper, a piecewise normalization approach is proposed to simulate moisture sensitivity test with both preconditioning absorption and reflow desorption phases. A bi-material model with analytical solutions...
System-in-a-Package (SiP) aims to integrate a functional sub-system with one or more semiconductor chips along with passive components onto a substrate. SiP is transferred molded to the OEM for second level assembly using industry standards and high volume equipment. In most recent applications (high I/O density, improved electrical performance), LGA (Land Grid Array) is a very practical solution...
In board manufacturing the shear test is frequently used to evaluate the quality of the solder joints shortly after the soldering process as well as after thermal cycling. The latter evaluation is in particular applied to leadless ceramic components; a certain load drop is linked to solder degradation in a certain region of the joint which is declared ??failed?? if the load drop of the shear force...
The paper reports three examples of best industrial practice showing the substantial benefits gained in terms of time-to-market reduction when virtual prototyping is enhanced by statistical and stochastic methodologies. These examples from a microelectronics setting of high volume component and module manufacturing deal with different fields: i) ball grid array (BGA) design optimization based on sophisticated...
This paper presents the investigation of the behaviour of BCB thin-film package based on the ANSYS FEM analysis. This kind of zero-level packaging has some stress effects on a packaged device causing deformation of chip and package cap itself. BCB cap deformation and device chip deformation as a function of its residual stress are significant due to the reliability of the packaged devices. It was...
In this paper, the Copper wirebonding technology is investigated. From a numerical point of view, the wirebonding process is modelled. Experiments on specially designed bondpads are performed in order to verify the models. As such, this leads to a thorough understanding of the wirebonding process, especially the forces that take a role during this process.
The typical approach to investigate the reliability of plastic packages is based on material characterizations. Thereby the material characterization is carried out using standard methods like Dynamic Mechanical Analysis (DMA) and Thermo-Mechanical Analysis (TMA). Based on these results the change of Epoxy Moulding Compounds (EMC) thermo-mechanical properties is used to predict long-term stress changes...
The current paper applies both molecular modeling and mesoscale modeling to determine modulus and defect formation in epoxy and epoxy-copper interfaces. The results will show that molecular modeling may be applied directly to parameterize the bead properties used in the mesoscale model, which scale to the physical properties.
In this work, we present a theoretical and experimental investigation into the response of an electrostatically actuated microbeam when subjected to drop-table test. For the theoretical part, a reduced-order model based on an Euler-Bernoulli beam model is utilized. The model accounts for the electrostatic bias on the microbeam and the shock pulse of the drop-table test. Simulation results are presented...
This paper describes chip solder joint reliability on three substrate types: one board SMI (aluminium substrate) and two different boards in FR4. Several chip sizes and types (resistor, capacitor) were assembled on these boards. Accelerated Thermal cycles (ATC) -55/+125??C were applied to evaluate the lifetime of chip solder joints. The different results obtained showed an important dispersion in...
The challenge of lithographic production of electronic circuitry on polymer foil is that deformations approaching the feature sizes of the circuitry can cause considerable overlay problems and thereby malfunctioning of the devices. The substrate foil is susceptible to several types of deformations. Accurate prediction of these deformations is of great importance, as it will help to improve the production...
Increasing demand, regarding to advanced 3D packages and high performance applications, accelerates the development of 3D silicon integrated circuit, with the aim to miniaturize and reduce cost. The study of the reliability of the through silicon via and of most critical areas for the emergence of failure remains a major concern. This paper deals with the variation of stress and strain induced in...
Despite the fact that epoxy has continuously used as encapsulant in electronic packaging, its joint with copper-based substrate is prone to delaminate during reliability test. A prime reason is the lack of adhesion between Cu and epoxy compound. To solve the problem, self-assembly molecular structure (SAM) is adopted to improve adhesion of epoxy-copper system. In seeing that hydrophobic behaviour...
Solar modules are typically qualified by conducting a sequence of industry standard tests, for example IEC 61215 and 61646. Although these tests are thorough and therefore also time consuming, the results cannot be used to determine the lifetime or make inferences about lifetime of the modules. New approaches are needed to fulfil requirements as designed lifetime typically 25 years and time-to-market...
The reliability of micro electromechanical systems depends directly on the mechanical behavior of microstructures and their performances are strongly associated with a good knowledge of materials mechanical properties that compose them. Thus, it is important to precisely determine these properties. There are various methods for micro-materials' characterization. In this work, we are interested in...
Humidity management of commercial-of-the-shelf electronic components in non-controlled climatic environments can be realized e.g. by introducing a local printed circuit board heater. By choosing appropriate size and location of the heater plate in the vicinity of the critical electronic packages, and utilizing logic control function, it is possible to improve the quality of local humidity management...
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