Architectural optimization for microelectronic packaging (original) (raw)

Reliability enhancement of electronic packages by design of optimal parameters

Microelectronics Reliability, 2004

Reliability growth testing involves the selection of optimal design parameters to enhance a product's reliability. This paper proposes a split plot experimental design that accommodates the restriction on randomization on the order of experimental runs caused by the experimental nature of accelerated reliability testing. The proposed experimental design provides statistically relevant solutions about the choice of design parameters, in terms of their reliability impact, in a much shorter time. A degradation model that aids in predicting the failure time for the given problem further supplements this discussion.

Reliability and cost optimization of electronic devices considering the component failure rate uncertainty

Reliability Engineering & System Safety, 2004

The objective of this paper is to present an efficient computational methodology to obtain the optimal system structure of electronic devices by using either a single or a multiobjective optimization approach, while considering the constraints on reliability and cost. The component failure rate uncertainty is taken under consideration and it is modeled with two alternative probability distribution functions. The Latin hypercube sampling method is used to simulate the probability distributions. An optimization approach was developed using the simulated annealing algorithm because of its flexibility to be applied in various system types with several constraints and its efficiency in computational time. This optimization approach can handle efficiently either the single or the multiobjective optimization modeling of the system design. The developed methodology was applied to a power electronic device and the results were compared with the results of the complete enumeration of the solution space. The stochastic nature of the best solutions for the single objective optimization modeling of the system design was sampled extensively and the robustness of the developed optimization approach was demonstrated. q

Integration of analytical techniques in stochastic optimization of microsystem reliability

Microelectronics Reliability, 2011

This paper presents an integrative application of several numerical analytical techniques and associated analysis tools for design optimization and damage prediction in electronics packages and microsystems. This design-for-reliability approach is based on four different types of numerical techniques that allow (1) high-fidelity modelling, (2) reduced order modelling, (3) numerical optimization and (4) uncertainty analysis. The capabilities and the characteristics of the methods that underpin these four types of modelling and analysis tools are firstly investigated. The integration of the methods and tools is then examined and a methodology for coupling the tools in an optimization process is proposed. This numerical methodology involves the following steps: (1) Define sampling points for the design of interest by design of experiments (DOE) and calculate the design response at each DOE point using high-fidelity analysis; (2) construct reduced order models (ROM) for fast analysis using the obtained response values at the DOE points; (3) Undertake deterministic optimization in the defined design space by ROM; and (4) Probabilistic optimization by including variation and uncertainty of the design in the optimization task. This approach is suitable to address design-for-reliability requirements at early design stages in a wide range of application areas. The application of this approach is demonstrated in a case for minimizing the thermal fatigue damage of flip-chip solder interconnects. Design modifications show that this approach can provide improved reliability of the package and in the same time satisfy a number of design requirements.

Reliability-and performance-based robust design optimization of MEMS structures considering technological uncertainties

The paper discusses the applicability of a reliability-and performance-based multicriteria robust design optimization technique for micro-electromechanical systems, considering their technological uncertainties. Nowadays, micro-devices are commonly applied systems, especially in the automotive industry, taking advantage of utilizing both the mechanical structure and electronic control circuit on one board. Their frequent use motivates the elaboration of virtual prototyping tools that can be applied in design optimization with the introduction of technological uncertainties and reliability. The authors present a procedure for the optimization of micro-devices, which is based on the theory of reliability-based robust design optimization. This takes into consideration the performance of a micro-device and its reliability assessed by means of uncertainty analysis. The procedure assumes that, for each checked design configuration, the assessment of uncertainty propagation is performed with the metamodeling technique. The described procedure is illustrated with an example of the optimization carried out for a finite element model of a micro-mirror. The multi-physics approach allowed the introduction of several physical phenomena to correctly model the electrostatic actuation and the squeezing effect present between electrodes. The optimization was preceded by sensitivity analysis to establish the design and uncertain domains. The genetic algorithms fulfilled the defined optimization task effectively. The best discovered individuals are characterized by a minimized value of the multi-criteria objective function, simultaneously satisfying the constraint on material strength. The restriction of the maximum equivalent stresses was introduced with the conditionally formulated objective function with a penalty component. The yielded results were successfully verified with a global uniform search through the input design domain.

Reliability modeling on a MOSFET power package based on embedded die technology

Microelectronics Reliability, 2010

Embedding of discrete semiconductors into substrates has the advantages of achieving high degree of miniaturization, good electrical performance and possible low cost. A MOSFET power package based on the embedded die technology was developed and the demonstrators were built. To reduce cost and time-to-market, thermo-mechanical virtual prototyping is applied to support the package development. 2D and 3D parametric FE models were established to conduct numerical simulations to investigate the thermo-mechanical reliability performance under packaging processes and test conditions. The package design and material variations, such as the thicknesses of the Cu layer and the resin in the RCC foil, the Bond Line Thickness (BLT), the thickness and material properties of prepreg, via dimensions and via-filling, were included in the parametric models. The root cause for die cracking, delamination between the interface die/RCC foil, and cracking of Cu vias were analyzed based on the simulation results. Verification of the modeling results was conducted through comparison with the test results. The results indicate that the prediction from the FE modeling matches reasonably well with the test results.

Structural Reliability of Novel 3-D Integrated Thermal Packaging for Power Electronics

Volume 10: Micro- and Nano-Systems Engineering and Packaging, 2015

The continual increase of device power and package integration levels has driven the development of advanced power electronics packaging solutions. This study will focus on a numerical modeling approach to design analysis and material selection to improve solder joint reliability in one of these advanced solutions — a thermally integrated power electronics package that aims to dissipate hot-spot heat flux (5 kW/cm2) via mini-contact based thermo-electric (TE) cooling in addition to removing background heat flux (1 kW/cm2) by manifold-microchannel cooling. The methodology used for performing the structural reliability modeling is a non-linear finite element analysis (FEA) approach. Combined thermal and mechanical analyses were run to obtain stresses and strains in the solder joint used to integrate the TE cooler with the mini-contact and the mini-contact with the Silicon Carbide (SiC) chip. To predict the Mean Time to Failure (MTTF) of SAC305 at various levels of integration, a Physi...

Advanced technologies for reliability-based design optimization

2007

In the Reliability-Based Design Optimization (RBDO) model for robust system design, the mean values of uncertain system variables are usually used as design variables, and the cost is optimized subject to prescribed probabilistic constraints as defined by a nonlinear mathematical programming problem. Therefore, a RBDO solution that reduces the structural weight in uncritical regions does not only provide an improved design but also a higher level of confidence in the design. In this work, we present recent developments for the RBDO model relative to two points of view: reliability and optimization. Next, we present our recent developments for reliability-based design optimization model. Finally, we demonstrate the efficiency of our methods on different applications.

Reliability-Based Design Guidance of Three-Dimensional Integrated Circuits Packaging Using Thermal Compression Bonding and Dummy Cu/Ni/SnAg Microbumps

Journal of Electronic Packaging, 2014

In the latest microelectronics industry, the emerging three-dimensional (3D) chip stacking technique using through silicon via (TSV) enables higher integration density that allows greater numbers of interconnections in order to fulfill the urgent requirements of dimensional downscaling and electrical speed enhancement. A high-density pitch of microbumps associated with the wafer-level underfill (WLUF) under a thermal compressions process are utilized to prevent the thermo-mechanical failures of the microbumps due to variations of thermal expansions of different materials in the 3D package. The use of dummy microbumps has been proposed to find the acceptable thin-layer uniformity and the reliable mechanical performances of the entire packaging structure. The warpage and strain behavior of packaging structure has been simulated by finite element analysis (FEA) and compared with experimental results. The responses were parametrically modeled using Kriging model with respect to compressive force, the thickness of the top chip, and the location of the dummy microbumps. The deterministic design guidance for warpage and strain has been obtained from the Kriging model. Furthermore, the reliability of the design under uncertainty has been investigated. A Reliability-Based Design Guidance has been proposed to provide a safety boundary in terms of the allowable reliability index. The proposed method can be utilized as the reliability standard for high-throughput production of 3D ICs packaging.

Some particular aspects of reliability evaluation of monolithic ICs

The paper gives an overview of the present situation in the domain, the front line in the battle for the best products. After a short introduction, the main problems arisen in reliability evaluation of monolithic integrated circuits, the evaluation itself and some new points of view concerning the dynamic life testing, screening and burn-in, accelerated tests, physics of failure of plastic encapsulated microcircuits (PEM) and process reliability are presented. Key words: Accelerated tests, best reliability of products, dynamic life testing and burn-in, evaluation of monolithic integrated circuits, physics of failure of PEM.