Investigation of residual stress effect during the anodic bonding process with different bondable materials for wafer level packaging design

2016 ◽  
Author(s):  
Xiaodong Hu ◽  
Maozhou Meng ◽  
Manuel Baeuscher ◽  
Ulli Hansen ◽  
Simon Maus ◽  
...  
Keyword(s):  
Residual Stress ◽  
Bonding Process ◽  
Anodic Bonding ◽  
Stress Effect ◽  
Wafer Level ◽  
Packaging Design ◽  
Wafer Level Packaging ◽  
Residual Stress Effect

Micromechanical Modeling of Viscoplastic Behavior of Laminated Polymer Composites With Thermal Residual Stress Effect

2016 ◽  
Vol 138 (3) ◽  
Author(s):  
Qiang Chen ◽  
Xuefeng Chen ◽  
Zhi Zhai ◽  
Xiaojun Zhu ◽  
Zhibo Yang
Keyword(s):  
Residual Stress ◽  
Polymer Matrix Composites ◽  
Micromechanical Model ◽  
Thermal Residual Stress ◽  
Micromechanical Modeling ◽  
Multiscale Approach ◽  
Stress Effect ◽  
Accurate Analysis ◽  
Rate Dependent ◽  
Residual Stress Effect

In this paper, a multiscale approach has been developed for investigating the rate-dependent viscoplastic behavior of polymer matrix composites (PMCs) with thermal residual stress effect. The finite-volume direct averaging micromechanics (FVDAM), which effectively predicts nonlinear response of unidirectional fiber reinforced composites, is incorporated with improved Bodner–Partom model to describe the viscoplastic behavior of PMCs. The new micromechanical model is then implemented into the classical laminate theory, enabling efficient and accurate analysis of multidirectional PMCs. The proposed multiscale theory not only predicts effective thermomechanical viscoplastic response of PMCs but also provides local fluctuations of fields within composite microstructures. The deformation behaviors of several unidirectional and multidirectional PMCs with various fiber configurations are extensively simulated at different strain rates, which show a good agreement with the experimental data found from the literature. Influence of thermal residual stress on the viscoplastic behavior of PMCs is closely related to fiber orientation. In addition, the thermal residual stress effect cannot be neglected in order to accurately describe the rate-dependent viscoplastic behavior of PMCs.

Wafer Level Micropackaging of MEMS Devices Using Thin Film Anodic Bonding

2002 ◽  
Vol 729 ◽  
Author(s):  
Lauren E. S. Rohwer ◽  
Andrew D. Oliver ◽  
Melissa V. Collins
Keyword(s):  
Shear Strength ◽  
Test Sample ◽  
Anodic Bonding ◽  
Mems Devices ◽  
Wafer Level ◽  
Thermal Actuators ◽  
Wafer Level Packaging ◽  
Hermetic Seal ◽  
Leak Testing ◽  
Before And After

AbstractA wafer level packaging technique that involves anodic bonding of Pyrex wafers to released surface micromachined wafers is demonstrated. Besides providing a hermetic seal, this technique allows full wafer release, provides protection during die separation, and offers the possibility of integration with optoelectronic devices. Anodic bonding was performed under applied voltages up to 1000 V, and temperatures ranging from 280 to 400°C under vacuum (10-4Torr). The quality of the bonded interfaces was evaluated using shear strength testing and leak testing. The shear strength of Pyrex-to-polysilicon and aluminum bonds was ∼10-15 MPa. The functionality of surface micromachined polysilicon devices was tested before and after anodic bonding. 100% of thermal actuators, 94% of torsional ratcheting actuators, and 70% of microengines functioned after bonding. The 70% yield was calculated from a test sample of 25 devices.

scholarly journals Superlayer Residual Stress Effect on the Indentation Adhesion Measurements

1999 ◽  
Vol 594 ◽  
Author(s):  
Alex A. Volinsky ◽  
Neville R. Moody ◽  
William W. Gerberich
Keyword(s):  
Residual Stress ◽  
Sputter Deposition ◽  
Work Of Adhesion ◽  
Stress Effect ◽  
Aluminum Films ◽  
Nanoindentation Testing ◽  
Deposition Parameters ◽  
Thin Aluminum ◽  
Residual Stress Effect ◽  
Sputter Deposited

AbstractThe practical work of adhesion has been measured in thin aluminum films as a function of film thickness and residual stress. These films were sputter deposited onto thermally oxidized silicon wafers followed by sputter deposition of a one micron thick W superlayer. The superlayer deposition parameters were controlled to produce either a compressive residual stress of 1 GPa or a tensile residual stress of 100 MPa. Nanoindentation testing was then used to induce delamination and a mechanics based model for circular blister formation was used to determine practical works of adhesion. The resulting measured works of adhesion for all films between 100 nm and 1 μm thick was 30 J/m2 regardless of superlayer stress. However, films with the compressively stressed superlayers produced larger blisters than films with tensile stressed superlayers. In addition, these films were susceptible to radial cracking producing a high variability in average adhesion values.

Residual Stress Effect on Performance of Diaphragm-Based MEMS Pressure Transducers

2000 ◽  
Author(s):  
Meng-Nian Niu ◽  
Eun Sok Kim
Keyword(s):  
Residual Stress ◽  
Theoretical Analysis ◽  
Layer Thickness ◽  
Compressive Residual Stress ◽  
Stress Effect ◽  
Layer By Layer ◽  
Pressure Transducers ◽  
Before And After ◽  
Supporting Layer ◽  
Residual Stress Effect

Abstract We experimentally and theoretically confirm that residual stress within a diaphragm is critical in limiting the performance of diaphragm-based piezoelectric microphones even if the stress is low (around 50 MPa). We have fabricated and studied microphones with Al/parylene/ZnO/SiN2/poly-Si/SiN1 (from top to bottom) diaphragm. As the SiN1 supporting layer is removed layer by layer from the backside with CF4 plasma (in an RIE system), we measure both the sensitivity and center displacement of the microphone before and after each RIE etching of the SiN1 from the microphone diaphragm, and find the sensitivity increasing about 5–16 times with the best sensitivity reaching 11 μV/μbar from a mere 0.6 μV/μbar. The center displacement increases very moderately as the SiN1 layer thickness decreases from 0.8 to 0.2 μm. However, the center displacement starts to increase greatly as the SiN1 layer thickness goes below 0.2 μm, which compares with our theoretical analysis well. In the case of the SiN1 layer having compressive residual stress, the compressive stress can enhance the microphone sensitivity and center displacement to a certain extent.

Residual Stress in Silicon Caused by Cu-Sn Wafer-Level Packaging

2013 ◽  
Author(s):  
Maaike M. V. Taklo ◽  
Astrid-Sofie Vardøy ◽  
Ingrid De Wolf ◽  
Veerle Simons ◽  
H. J. van de Wiel ◽  
...  
Keyword(s):  
Residual Stress ◽  
Integrated Circuit ◽  
High Performance ◽  
White Light Interferometry ◽  
Wafer Level ◽  
Noticeable Effect ◽  
Micro Raman Spectroscopy ◽  
Wafer Level Packaging ◽  
Mems Device ◽  
Specific Technology

The level of stress in silicon as a result of applying Cu-Sn SLID wafer level bonding to hermetically encapsulate a high-performance infrared bolometer device was studied. Transistors are present in the read out integrated circuit (ROIC) of the device and some are located below the bond frame. Test vehicles were assembled using Cu-Sn SLID bonding and micro-Raman spectroscopy was applied on cross sectioned samples to measure stress in the silicon near the bond frame. The test vehicles contained cavities and the bulging of the structures was studied using white light interferometry. The test vehicles were thermally stressed to study possible effects of the treatments on the level of stress in the silicon. Finite element modeling was performed to support the understanding of the various observations. The measurements indicated levels of stress in the silicon that can affect transistors in regions up to 15 μm below the bond frame. The observed levels of stress corresponded well with the performed modeling. However, no noticeable effect was found for the ROIC used in this work. The specific technology used for the fabrication of the ROIC of a MEMS device is thus decisive. The level of stress did not appear to change as a result of the imposed thermal stress. The level of stress caused by the bond frame can be expected to stay constant throughout the lifetime of a device.

Numerical Calculation of Residual Stress Corrected J-Integral Using ABAQUS

2014 ◽  
Author(s):  
Xian-Kui Zhu
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Stress Field ◽  
Residual Stresses ◽  
Stress Effect ◽  
J Integral ◽  
Residual Stress Field ◽  
Path Independence ◽  
Residual Stress Effect ◽  
Senb Specimen

Residual stresses exist in welded structures due to thermal stresses. Without temperature change, large plastic deformation can result in “cold” residual stresses in a wrinkle or dent in a metallic pipe. For a crack in residual stress field, residual stresses might have strong effect on fracture parameter, the J-integral. In order to ensure its path-independence, different correction methods have been developed in consideration of residual stress effect. Recently, the finite element commercial software ABAQUS adopted one of the correction methods, and is able to calculate the residual stress corrected J-integral. A brief review is first given to the J-integral definition, the conditions of path-independence or path-dependence, and the modifications to consider the residual stress effect. A modified single edge-notched bend (SENB) specimen is then used, and a numerical procedure is developed for ABAQUS to evaluate the path-independence of the residual stress corrected J-integral. Detailed elastic-plastic finite element analyses are performed for the SENB specimen in three-point bending. The residual stress field, crack-tip stress field, and J-integral with and without consideration of residual stresses are discussed.

scholarly journals A Method of Fabricating Vacuum Packages with Vertical Feedthroughs in a Wafer Level Anodic Bonding Process

2014 ◽  
Vol 87 ◽  
pp. 887-890 ◽  
Author(s):  
Mustafa Mert Torunbalci ◽  
Said Emre Alper ◽  
Tayfun Akin
Keyword(s):  
Bonding Process ◽  
Anodic Bonding ◽  
Wafer Level
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