Wafer-level experimental study of residual stress in AlN-based bimorph piezoelectric micromachined ultrasonic transducer

2020 ◽  
Vol 2 (4) ◽  
pp. 045013
Author(s):  
Joontaek Jung ◽  
Jean-Claude Bastien ◽  
Aude Lefevre ◽  
Kevin Benedetto ◽  
Rémy Dejaeger ◽  
...  
Keyword(s):  
Residual Stress ◽  
Experimental Study ◽  
Ultrasonic Transducer ◽  
Wafer Level

Extensive Experimental Study on Diaphragm-Based Piezoelectric Microphone

1999 ◽  
Author(s):  
Meng-Nian Niu ◽  
Hong Zeng ◽  
Hai Yan ◽  
Eun Sok Kim
Keyword(s):  
Residual Stress ◽  
Experimental Study ◽  
Acoustic Pressure ◽  
Structural Integrity ◽  
Vertical Displacement ◽  
Active Area ◽  
Zno Film ◽  
Beam Laser ◽  
Acoustic Chamber ◽  
Focused Beam

Abstract This paper reports our extensive experimental study on diaphragm-based piezoelectric microphones fabricated on a silicon substrate. We have fabricated and carefully analyzed about 60 micromachined piezoelectric microphones (composed of piezoelectric ZnO film, insulating layers and electrodes) built on a low-stress silicon nitride diaphragm (with and without corrugation on the diaphragm and with five kinds of residual stress in the diaphragm). Microphone sensitivity is measured in an acoustic chamber with a B&K4135 microphone. Vertical displacement of a microphone diaphragm under an applied acoustic pressure is measured with a focused-beam laser Doppler displacement meter. Our results show that (1) corrugation releases both tensile stress and compressive stress effectively, and increases the center displacement greatly, (2) a good bending curvature in the active area is needed for a good microphone sensitivity, and (3) ZnO structural integrity is the major factor that affects the bending curvature in the active area.

Experimental Study of Residual Stress Formation Mechanism of 7050 Aluminum Alloy Sheet by Laser Shock Processing

2016 ◽  
Vol 43 (7) ◽  
pp. 0702008
Author(s):  
曹宇鹏 Cao Yupeng ◽  
徐影 Xu Ying ◽  
冯爱新 Feng Aixin ◽  
花国然 Hua Guoran ◽  
周东呈 Zhou Dongcheng ◽  
...  
Keyword(s):  
Residual Stress ◽  
Experimental Study ◽  
Aluminum Alloy ◽  
Alloy Sheet ◽  
Laser Shock ◽  
Aluminum Alloy Sheet ◽  
Laser Shock Processing ◽  
7050 Aluminum Alloy ◽  
Stress Formation ◽  
Shock Processing

scholarly journals Experimental study on residual stress of milling medical magnesium alloy

2018 ◽  
Vol 397 ◽  
pp. 012046
Author(s):  
Yang Qiao ◽  
Peiquan Guo ◽  
Shouren Wang ◽  
Xuefeng Yang
Keyword(s):  
Residual Stress ◽  
Experimental Study ◽  
Magnesium Alloy

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.

Experimental Study on Residual Stresses of Al2O3 Coating by Laser Re-Melting

2010 ◽  
Vol 431-432 ◽  
pp. 446-449
Author(s):  
De Jun Kong ◽  
Kai Yu Luo ◽  
Hong Miao
Keyword(s):  
Residual Stress ◽  
Experimental Study ◽  
Tensile Stress ◽  
Residual Stresses ◽  
High Power ◽  
Bonding Strength ◽  
Strengthening Mechanism ◽  
Al2o3 Coating ◽  
Micro Hardness ◽  
Continuous Co2 Laser

The surface of Al2O3 coating sprayed on 40Cr substrate was re-melted with high power continuous CO2 laser, and its micro-hardness and residual stresses were measured, respectively. The strengthening mechanism of Al2O3 coating by laser re-melting was analyzed and discussed. The experimental results shown that the surface of Al2O3 coating by laser re-melting is neat and smooth, and its compositions are even, its structures are compact, and Al2O3 coating is evenly distributed in its surface with grain forms, and its micro-hardness increases about 200%; Residual stress of Al2O3 coating by laser re-melting is changed into compressive stress from tensile stress, which is benefit to improving bonding strength of coating-substrate interface.

Experimental Study on Residual Stress of K24 Superalloy in Laser Cladding Zone by Laser Shock Processing

2007 ◽  
Vol 353-358 ◽  
pp. 453-456
Author(s):  
Jin Zhon Lu ◽  
Yong Kang Zhang ◽  
Y.Y. Xu ◽  
De Jun Kong ◽  
H.B. Yao ◽  
...  
Keyword(s):  
Residual Stress ◽  
Experimental Study ◽  
Laser Cladding ◽  
Compressive Residual Stress ◽  
Laser Shock ◽  
Laser Shock Processing ◽  
X Ray ◽  
Tempering Treatment ◽  
Shock Processing ◽  
Improve Fatigue

The surface of K24 superalloy was processed with laser cladding & LSP (laser shock processing). Residual stress in the laser cladding zone by LSP was measured with X-ray stress tester X-350A, and the variational rule of residual stress in the cladding zone by tempering treatment of 8 hours and 16 hours was measured, respectively. The experimental results show that compressive residual stress of K24 superalloy surface by laser cladding & laser shock processing is above -600MPa, which exceeds residual stress by mechanical peening treatment; and there is no clear effect on residual stress by tempering treatment at 600°C for 8 hours and 16 hours, respectively, which can improve fatigue life of K24 superalloy.

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