Anisothermal Anodic Bonding: A Method to Control Global Curvature and Residual Stress

2019 ◽  
Vol 33 (4) ◽  
pp. 563-572 ◽  
Author(s):  
Manish Yadav ◽  
Tung-Wei Lin ◽  
Harley T. Johnson ◽  
Gavin P. Horn
Keyword(s):  
Residual Stress ◽  
Anodic Bonding ◽  
Global Curvature

An Investigation of Residual Stress Effects due to the Anodic Bonding of Glass and Silicon in MEMS Fabrication

2006 ◽  
Vol 5-6 ◽  
pp. 501-508 ◽  
Author(s):  
I. Sadaba ◽  
Colin H.J. Fox ◽  
Stewart McWilliam
Keyword(s):  
Residual Stress ◽  
Anodic Bonding ◽  
Fe Model ◽  
Moderate Pressure ◽  
Mems Devices ◽  
Wafer Level ◽  
Micro Electro Mechanical Systems ◽  
Ion Migration ◽  
Compositional Gradients ◽  
Rate Sensor

Anodic bonding is widely-used in the fabrication of Micro-Electro-Mechanical Systems (MEMS) devices to join silicon and glass components. The process involves the application of temperature, moderate pressure and an electric field. This paper investigates residual stresses arising during anodic bonding, focusing on the resulting induced distortions. Components of a MEMS silicon rate sensor, in which a silicon wafer is anodically bonded to Pyrex™ glass, were used as the vehicle for the investigation. Distortions generated by the anodic bonding process when using two different electrode configurations (point and planar) were measured using a surface optical profiler. These showed a particular pattern across the wafers for both configurations. An efficient FEM study was carried out to model the qualitative effect of the following residual stress sources; thermal stress, glass shrinkage due to structural relaxation and compositional gradients due to ion migration. Importantly, the FE model takes account the actual multi-device wafer-level configuration, as opposed to a single device. The results demonstrate that compositional gradients can make a significant contribution to the observed pattern of distortions.

Anodic Bonding Mechanism of Pyrex Glass and Kovar Alloy and its Residual Stress Analysis

2014 ◽  
Vol 922 ◽  
pp. 435-440 ◽  
Author(s):  
Cui Rong Liu ◽  
Hui Qin Chen ◽  
Juan Li ◽  
Qing Sen Meng
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Transition Layer ◽  
Chemical Elements ◽  
Alloy Layer ◽  
Anodic Bonding ◽  
Pyrex Glass ◽  
Glass Layer ◽  
Residual Stresses And Strains ◽  
Kovar Alloy

Anodic bonding experiments of Pyrex glass and Kovar alloy have been carried out in this investigation. By means of SEM and EDS, microstructures and chemical elements in the joining interfaces were analyzed. With XRD, phase structures in the interfaces were also analyzed. The results show that the joint is made up of three different layers, which are Kovar alloy layer, transition layer and Pyrex glass layer. The transition layer are spinal oxides, which are FeO·SiO2. By means of MARC software, residual stresses and strains were investigated for the anodic bonding samples of Pyrex glass/Kovar alloy. The maximum residual stress located in the transition layer and the maximum strain located in the Kovar alloy layer. Residual stresses and strains of the sample are significant small and uniform.

TEM investigations of surface residual stress relaxation in A12O3 and Al2O3-SiC nanocomposite

1994 ◽  
Vol 52 ◽  
pp. 628-629
Author(s):  
J. Fang ◽  
H. M. Chan ◽  
M. P. Harmer
Keyword(s):  
Residual Stress ◽  
Single Phase ◽  
Stress Relief ◽  
Stress Recovery ◽  
Surface Residual Stress ◽  
Microscopic Mechanism ◽  
Sic Particles ◽  
Annealing Procedure ◽  
The Difference ◽  
Nano Size

It was Niihara et al. who first discovered that the fracture strength of Al2O3 can be increased by incorporating as little as 5 vol.% of nano-size SiC particles (>1000 MPa), and that the strength would be improved further by a simple annealing procedure (>1500 MPa). This discovery has stimulated intense interest on Al2O3/SiC nanocomposites. Recent indentation studies by Fang et al. have shown that residual stress relief was more difficult in the nanocomposite than in pure Al2O3. In the present work, TEM was employed to investigate the microscopic mechanism(s) for the difference in the residual stress recovery in these two materials.Bulk samples of hot-pressed single phase Al2O3, and Al2O3 containing 5 vol.% 0.15 μm SiC particles were simultaneously polished with 15 μm diamond compound. Each sample was cut into two pieces, one of which was subsequently annealed at 1300° for 2 hours in flowing argon. Disks of 3 mm in diameter were cut from bulk samples.

Residual stress measurements and modeling of built-up Box-T sections

2021 ◽  
Vol 160 ◽  
pp. 107336
Author(s):  
Ziqian Zhang ◽  
Gang Shi ◽  
Xuesen Chen ◽  
Lijun Wang ◽  
Le Zhou
Keyword(s):  
Residual Stress ◽  
Stress Measurements

Comparative study of the effective parameters on residual stress relaxation in welded aluminum plates under cyclic loading

2020 ◽  
Vol 21 (5) ◽  
pp. 505
Author(s):  
Yousef Ghaderi Dehkordi ◽  
Ali Pourkamali Anaraki ◽  
Amir Reza Shahani
Keyword(s):  
Residual Stress ◽  
Cyclic Loading ◽  
Stress Relaxation ◽  
Stress Amplitude ◽  
Cyclic Plasticity ◽  
Mean Stress ◽  
Effective Parameters ◽  
Perfect Plasticity ◽  
Residual Stress Relaxation ◽  
Aluminum Plates

The prediction of residual stress relaxation is essential to assess the safety of welded components. This paper aims to study the influence of various effective parameters on residual stress relaxation under cyclic loading. In this regard, a 3D finite element modeling is performed to determine the residual stress in welded aluminum plates. The accuracy of this analysis is verified through experiment. To study the plasticity effect on stress relaxation, two plasticity models are implemented: perfect plasticity and combined isotropic-kinematic hardening. Hence, cyclic plasticity characterization of the material is specified by low cycle fatigue tests. It is found that the perfect plasticity leads to greater stress relaxation. In order to propose an accurate model to compute the residual stress relaxation, the Taguchi L18 array with four 3-level factors and one 6-level is employed. Using statistical analysis, the order of factors based on their effect on stress relaxation is determined as mean stress, stress amplitude, initial residual stress, and number of cycles. In addition, the stress relaxation increases with an increase in mean stress and stress amplitude.

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