Seungbae Park

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We propose an advanced thermal-moisture analogy scheme to cope with the inherent limitations of the existing analogy schemes. The new scheme is based on the experimentally observed unique hygroscopic behavior of polymeric materials used in microelectronics; i.e., the saturated concentration is only a function of relative humidity regardless of temperature.(More)
A noncontact, fast, accurate, low-cost, broad-range, full-field, easy-to-implement three-dimensional (3D) shape measurement technique is presented. The technique is based on a generalized fringe projection profilometry setup that allows each system component to be arbitrarily positioned. It employs random phase-shifting, multifrequency projection fringes,(More)
The stresses due to moisture saturation on microelectromechanical systems (MEMS) sensor devices after exposure to temperature cycling have been addressed. Moisture-, temperature-, and time-dependent material property of molding compounds for the MEMS devices were characterized. To determine the coefficient of hygroscopic swelling of a molding compound and(More)
Optical microscopy was used to discern the different grain orientations and grain boundaries on the polished cross-sections of neareutectic lead-free board-level SnAgCu (SAC) solder interconnects. Strain distributions with submicron accuracy of the deformations on the cross-sections of the solder interconnects were measured when the package was subjected to(More)
This paper develops an assessment methodology based on vibration tests and finite element analysis (FEA) to predict the fatigue life of electronic components under random vibration loading. A specially designed PCB with ball grid array (BGA) packages attached was mounted to the electro-dynamic shaker and was subjected to different vibration excitations at(More)
The peak value of out-of-plane displacement of printed circuit board (PCB), when it is subjected to drop impact, is a major concern to electronic manufacturers as it relates to the maximum stress causing failure for the solder balls. In this work, the full-field dynamic responses of printed circuit boards (PCBs) of product level are measured and analyzed in(More)
Thanh Tung Nguyen a,c, Nam Seo Goo b,c,∗,1, Vinh Khanh Nguyen c, Youngtai Yoo d, Seungbae Park e a Department of Aerospace Engineering, Konkuk University, Gwangjin-gu, Seoul 143-701, Republic of Korea b Smart Microsystem Research Laboratory, Department of Advanced Technology Fusion, Konkuk University, Gwangjin-gu, Seoul 143-701, Republic of Korea c(More)
Moisture can have significant effects on the performance and reliability of electronic components. Accurately simulating moisture diffusion is important for designers and manufacturers to obtain a realistic reliability evaluation. Beginning with version 14, ANSYS is capable of simulating diffusion and related behaviors, such as hygroscopic swelling, with(More)
Digital image correlation and cross polarizer, optical microscopy were used to quantify the deformation behavior under deep thermal cycling of near eutectic SnAgCu (SAC) solder in board level interconnects. Maps with sub micron spatial resolution of the strain levels and von Mises strain were produced for selected cross sections. Large spatial variations in(More)