Design Optimization of a Wafer Level Package for Surface Acoustic Wave Filters

2007 ◽  
Author(s):  
Jupyo Hong ◽  
Shan Gao ◽  
Job Ha ◽  
Sijoong Yang ◽  
Ingoo Kang ◽  
...  
Keyword(s):  
Acoustic Wave ◽  
Surface Acoustic Wave ◽  
Three Dimensional ◽  
Wafer Level ◽  
Filling Materials ◽  
Dimensional Finite Element ◽  
Via Holes ◽  
Cte Mismatch ◽  
Via Hole ◽  
Three Dimensional Finite Element

In this paper, wafer level packaging of a surface acoustic wave (SAW) filter is considered. Numerical studies based on a three-dimensional finite element method (FEM) have been conducted in order to evaluate the reliability of a wafer level SAW package. The effects of package geometric parameters, such as the diameter of via hole and wafer thickness, on the reliability of the wafer level SAW package have been studied. The results show that the diameter of via hole for interconnection plays a key role in the reliability of the SAW package because the CTE mismatch between the filling materials of via holes (copper) and surrounding cap wafer martial (LiTiO3) is the highest among the material pairs in the package. Such CTE mismatch leads to the maximum stresses and warpages. The optimal thermo-mechanical properties of packaging materials have been proposed to achieve the minimum thermal stress during reflow process. Moreover, numerical results have also been compared with the experimental ones to validate the FEM model.

scholarly journals Three-Dimensional Finite Element Analysis and Characterization of Quasi-Surface Acoustic Wave Resonators

Micromachines ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1118
Author(s):  
Wen Chen ◽  
Linwei Zhang ◽  
Shangshu Yang ◽  
Wenhan Jia ◽  
Songsong Zhang ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Acoustic Wave ◽  
Resonant Frequency ◽  
Three Dimensional ◽  
High Accuracy ◽  
Element Analysis ◽  
Dimensional Finite Element ◽  
3D Fea ◽  
Three Dimensional Finite Element

In this work, three-dimensional finite element analysis (3D FEA) of quasi-surface acoustic wave (QSAW) resonators with high accuracy is reported. The QSAW resonators consist of simple molybdenum (Mo) interdigitated transducers (IDT) on solidly mounted stacked layers of AlN/Mo/Si. Different to the SAW resonators operating in the piezoelectric substrates, the reported resonators are operating in the QSAW mode, since the IDT-excited Rayleigh waves not only propagate in the thin piezoelectric layer of AlN, but also penetrate the Si substrate. Compared with the commonly used two-dimensional (2D) FEA approach, the 3D FEA method reported in this work shows high accuracy, in terms of the resonant frequency, temperature coefficient of frequency (TCF), effective coupling coefficient (keff2) and frequency response. The fabricated QSAW resonator has demonstrated a keff2 of 0.291%, series resonant frequency of 422.50 MHz, and TCF of −23.418 ppm/°C in the temperature range between 30 °C and 150 °C, for the design of wavelength at 10.4 μm. The measurement results agree well with the simulations. Moreover, the QSAW resonators are more mechanically robust than lamb wave devices and can be integrated with silicon-based film bulk acoustic resonator (FBAR) devices to offer multi-frequency function in a single chip.

Finite Element Analysis of Nonuniformity of Tires with Imperfections5

2007 ◽  
Vol 35 (3) ◽  
pp. 226-238 ◽  
Author(s):  
K. M. Jeong ◽  
K. W. Kim ◽  
H. G. Beom ◽  
J. U. Park
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Element Model ◽  
Radial Force ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Dimensional Finite Element ◽  
Force Variation ◽  
Three Dimensional Finite Element

Abstract The effects of variations in stiffness and geometry on the nonuniformity of tires are investigated by using the finite element analysis. In order to evaluate tire uniformity, a three-dimensional finite element model of the tire with imperfections is developed. This paper considers how imperfections, such as variations in stiffness or geometry and run-out, contribute to detrimental effects on tire nonuniformity. It is found that the radial force variation of a tire with imperfections depends strongly on the geometrical variations of the tire.

Tire Modeling by Finite Elements

1992 ◽  
Vol 20 (1) ◽  
pp. 33-56 ◽  
Author(s):  
L. O. Faria ◽  
J. T. Oden ◽  
B. Yavari ◽  
W. W. Tworzydlo ◽  
J. M. Bass ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Rolling Contact ◽  
Test Problems ◽  
State Behavior ◽  
Normal Contact ◽  
New Developments ◽  
Applied Torque ◽  
Dimensional Finite Element ◽  
Tire Modeling ◽  
Three Dimensional Finite Element

Abstract Recent advances in the development of a general three-dimensional finite element methodology for modeling large deformation steady state behavior of tire structures is presented. The new developments outlined here include the extension of the material modeling capabilities to include viscoelastic materials and a generalization of the formulation of the rolling contact problem to include special nonlinear constraints. These constraints include normal contact load, applied torque, and constant pressure-volume. Several new test problems and examples of tire analysis are presented.

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