Thermal Fatigue Reliability Analysis and Structural Optimization Based on a Robust Method for Microelectronics FBGA Packages

Abstract

In this paper, we propose a mixed robust method based on three-level and second-order experiment design, the quadric surface, and finite-element analysis to analyze and optimize thermal fatigue reliability of an FBGA package. According to structural characteristics of FBGA packages, six design variables are selected as optimized objects. The equivalent thermal fatigue strain of solder joints of FBGA packages is used as an objective function of thermal fatigue reliability optimization design. Threelevel and second-order experiment design was carried out for six design variables, and the equivalent thermal strain of solder joints was calculated by finite-element analysis according to experiment design. Then a quadric surface model of six design variables and the equivalent thermal strain of solder joints was built, and variance analysis and accuracy verification were performed. From the model and significance analysis, the nonlinear relation between design variables and thermal strain of solder joints, and the interaction among design parameters were obtained. Finally, a thermal fatigue robust optimization model was built, and optimum structural parameters and equivalent thermal fatigue strain of solder joints were obtained. Equivalent thermal fatigue strain decreased from 0.01858200 to 0.00951976 and was reduced by 48.77%, as shown by comparing the thermal strains before and after optimization.Index Terms-FBGA package, three-level and second-order experiment design, quadric surface, thermal fatigue reliability, robust optimization design.

System Identification and Dynamic Analysis of the Propulsion Shaft Systems Using Response Surface Optimization Technique

“…For this, the response surface optimization (RSO) technique is proposed in this paper. RSO is a mathematical optimization technique that has been utilized in the past for optimizing process parameters in casting and welding, as well as reliability and fatigue optimization studies of electronic packages [18][19][20]. Despite its proven effectiveness in other dynamic systems, it has yet to be applied in complex systems, such as marine shaft lines.…”

Efficient analytical moments for the robustness analysis in design optimisation

“…The advanced design optimisation paradigm that incorporates both such analyses is known as the reliability‐based robust design optimisation (RBRDO) [4, 5]. Though this method is predominantly used in the field of a structural and mechanical design, in the recent years, it has become increasingly popular in the other fields of engineering such as magnetics, manufacturing, microelectronics and micromachining [6–8] etc. due to the increasingly competitive market conditions, stringent safety requirements and the ability of the method to deliver designs that are insensitive to uncontrollable variations [7].…”

“…At the same time, such an analysis is essential as some design problems, e.g. advanced microelectronics package design [6], have a relatively large number of input variables ().…”