scholarly journals Die-Attach Structure of Silicon-on-Glass MEMS Devices Considering Asymmetric Packaging Stress and Thermal Stress

Sensors ◽  
2019 ◽  
Vol 19 (18) ◽  
pp. 3979
Author(s):  
Jun Eon An ◽  
Usung Park ◽  
Dong Geon Jung ◽  
Chihyun Park ◽  
Seong Ho Kong
Keyword(s):  
Thermal Stress ◽  
Silicon Wafers ◽  
Experimental Results ◽  
Mems Devices ◽  
Microelectromechanical System ◽  
Die Attach ◽  
Lack Of Control ◽  
Die Bonding ◽  
Glass Process ◽  
Typical Process

Die attach is a typical process that induces thermal stress in the fabrication of microelectromechanical system (MEMS) devices. One solution to this problem is attaching a portion of the die to the package. In such partial die bonding, the lack of control over the spreading of the adhesive can cause non-uniform attachment. In this case, asymmetric packaging stress could be generated and transferred to the die. The performance of MEMS devices, which employ the differential outputs of the sensing elements, is directly affected by the asymmetric packaging stress. In this paper, we proposed a die-attach structure with a pillar to reduce the asymmetric packaging stress and the changes in packaging stress due to changes in the device temperature. To verify the proposed structure, we fabricated four types of differential resonant accelerometers (DRA) with the silicon-on-glass process. We confirmed experimentally that the pillar can control the spreading of the adhesive and that the asymmetric packaging stress is considerably reduced. The simulation and experimental results indicated that the DRAs manufactured using glass-on-silicon wafers as handle substrates instead of conventional glass wafers have a structure that compensates for the thermal stress.

Influence of adhesive non-uniformity on zero offset of micro accelerometer

2017 ◽  
Vol 31 (31) ◽  
pp. 1750242 ◽  
Author(s):  
Wu Zhou ◽  
Fei Li ◽  
Huijun Yu ◽  
Hao Qu ◽  
Rui Hao ◽  
...  
Keyword(s):  
Thermal Stress ◽  
Mems Devices ◽  
Voltage Output ◽  
Die Attach ◽  
Environment Temperature ◽  
Zero Offset ◽  
Zero Voltage ◽  
Sensitive Direction ◽  
Different Levels ◽  
Micro Accelerometer

Adhesive attaching is a common method used in the packaging of high accurate MEMS devices. A full understanding of the effects of adhesive on device performance, therefore, plays a significant role in MEMS design because the thermal stress formed in packaging process highly depends on the shape, size, amount, properties and layout of the die attach adhesive. This paper investigates intensively the influence of adhesive nonuniformity in the sensitive direction of microaccelerometers on the distribution of thermal stress during the variation of environment temperature. The thermal stress will induce a movement of anchors and lead to nonzero voltage output of microaccelerometer. The influence of the adhesive with different levels of nonuniformity [Formula: see text] on zero voltage output is investigated and the results show that the adhesive nonuniformity significantly influences the zero offset of the sensors, and the maximum one can reach 8.6 mV when nonuniformity factor is 0.975.

scholarly journals Temperature-Insensitive Structure Design of Micromachined Resonant Accelerometers

Sensors ◽  
2019 ◽  
Vol 19 (7) ◽  
pp. 1544 ◽  
Author(s):  
Yonggang Yin ◽  
Zhengxiang Fang ◽  
Yunfeng Liu ◽  
Fengtian Han
Keyword(s):  
Thermal Stress ◽  
Temperature Sensitivity ◽  
Structure Design ◽  
Experimental Results ◽  
Stress Effect ◽  
Glass Technology ◽  
Temperature Drift ◽  
Die Attach ◽  
Bias Stability

Micromachined resonant accelerometers (MRAs), especially those devices fabricated by silicon on glass technology, suffer from temperature drift error caused by inherent thermal stress. This paper proposes two structure designs to attenuate the effect of thermal stress. The first MRA structure is realized by optimizing the locations of the bonding anchors and utilizing a special-shaped substrate to isolate the thermal stress generated during the die attach process. The second structure is designed using an isolation frame fixed by a single anchor to replace all dispersed anchors associated with the suspension beams and micro-levers. Simulated and experimental results show that both of the MRA structures can effectively reduce the thermal stress effect. The experimental results on one MRA prototype indicate that the differential temperature sensitivity reduces down to 1.9 μg/°C and its 15-day bias stability reaches 1.4 μg.

Analysis of Two Electrical Failures Caused by Die Attach of Exposed Pad Package

2014 ◽  
Author(s):  
Jinglong Li ◽  
Motohiko Masuda ◽  
Yi Che ◽  
Miao Wu
Keyword(s):  
Bonding Process ◽  
Die Attach ◽  
Die Bonding ◽  
Generic Analysis

Abstract Die attach is well known in die bonding process. Its electrical character is simple. But some failures caused by die attach are not so simple. And it is not proper to analyze by a generic analysis flow. The analysis of two failures caused by die attach are presented in this paper.

scholarly journals Reducing the Hygroscopic Swelling in MEMS Sensor using Different Mold Materials

2020 ◽  
Vol 10 (1) ◽  
pp. 494
Author(s):  
Pinki Kumari ◽  
Kuldeep Singh ◽  
Anuj Singal
Keyword(s):  
Performance Analysis ◽  
Pressure Sensor ◽  
Ceramic Mold ◽  
Mems Devices ◽  
Challenging Problem ◽  
Microelectromechanical System ◽  
Saturation Concentration ◽  
Mems Sensor ◽  
Hygroscopic Swelling

Today, Hygroscopic swelling is one of the biggest challenging problem of Epoxy mold compound (EMC) in packaging with Microelectromechanical system (MEMS) devices. To overcome this hygroscopic swelling problem of EMC and guard the devices, MEMS devices are molded in this paper with different Mold Compound (MC) i.e. titanium and ceramic etc. during their interconnection with the board. Also, a comparatively performance analysis of this various mold compound with MEMS pressure sensor has been studied in this paper at 60% humidity, 140 mol/m<sup>3</sup> saturation concentration and 25 <sup>o</sup>C. It was observed that hygroscopic swelling does not take place in the titanium mold compound. But, titanium is very costly so we have to consider something cheaper material i.e. ceramic in this paper. The Hygroscopic swelling in Ceramic Mold Compound after 1 year is nearly 0.05mm which is very less than epoxy.

Ink-jetting for Electronic Assembly

2010 ◽  
Vol 2010 (1) ◽  
pp. 000929-000934
Author(s):  
Georg Meyer-Berg ◽  
Gottfried Beer ◽  
Klaus Pressel
Keyword(s):  
Void Formation ◽  
Experimental Results ◽  
Special Focus ◽  
Electronic Assembly ◽  
Filler Size ◽  
Die Attach ◽  
Ink Jet ◽  
The Future

We report experimental results on applying ink-jetting to dedicated system-in-package technologies. Special focus is on die-attach, vertical and horizontal interconnects. Our experiments on die attach experiments demonstrate that today we have still too high expenses to adapt materials, filler size and viscosity. The filling experiments of 150μm diameter vertical through encapsulant vias for package-on-package applications with ink-jetting showed void formation, which requires still smaller ink jet drops in the future. For formation of horizontal interconnects, e.g. for rerouting, by ink-jetting we observe that a functionalization of the surfaces e.g. with plasma or sulfur acid is required. Based on these project results and experience we suggest a roadmap for ink-jetting using parallel nozzles and single nozzles.

Effects of Packaging Induced Stress on MEMS Devices and Its Improvements

2006 ◽  
Vol 326-328 ◽  
pp. 529-532
Author(s):  
Sung Hoon Choa ◽  
Moon Chul Lee ◽  
Yong Chul Cho
Keyword(s):  
Silicon On Insulator ◽  
Anodic Bonding ◽  
Mems Devices ◽  
Wafer Level ◽  
Process Technology ◽  
Molding Compound ◽  
Mems Packaging ◽  
Induced Stress ◽  
Induced Structure ◽  
Glass Process

In MEMS, packaging induced stress or stress induced structure deformation becomes increasing concerns since it directly affects the performance of the device. The conventional MEMS SOI (silicon-on-insulator) gyroscope, packaged using the anodic bonding at the wafer level and EMC (epoxy molding compound) molding, has a deformation of MEMS structure caused by thermal expansion mismatch. Therefore we propose a packaged SiOG (Silicon On Glass) process technology and more robust spring design.

Numerical Simulation of Pre-Crack Propagation in ZrB2-SiC-AlN Ceramics Subjected to Thermal Shock

2013 ◽  
Vol 833 ◽  
pp. 154-158
Author(s):  
Xiao Yang Wan ◽  
Jun Liang ◽  
Guo Dong Fang ◽  
Ling Ling Wang
Keyword(s):  
Numerical Simulation ◽  
Thermal Stress ◽  
Crack Propagation ◽  
Thermal Shock ◽  
Dimensionless Parameter ◽  
Experimental Results ◽  
Force Model ◽  
Quenching Temperature ◽  
Depth Direction ◽  
Good Agreement

The present work examines the pre-indented crack propagation in ZrB2-SiC-AlN ceramics subjected to thermal shock under different temperature differences. A cohesive force model is applied according to the shape and characteristics of the crack in the indentation - quenching experiments. A dimensionless parameter is introduced to characterize the effect of depth on thermal stress which considers the cracks propagate along both the surface and the depth direction. The modified numerical results are 11.3%, 16.6%, 20.8% 27.1% and 64.6% at the quenching temperature differences of 240°C, 280°C, 320°C and 360°C, respectively, which are in good agreement with the experimental results.

Effect of Material Properties and Thickness of Die Attach on Delamination of Die Attach/Die Paddle Interface in Electronic Package

2010 ◽  
Author(s):  
Chia-Lung Chang ◽  
Po-Hsien Li
Keyword(s):  
Material Properties ◽  
Coefficient Of Thermal Expansion ◽  
Damage Parameter ◽  
Stress And Strain ◽  
Thermal Expansion Mismatch ◽  
The Finite Element Method ◽  
Electronic Package ◽  
Die Attach ◽  
Encapsulation Process ◽  
Die Bonding

The electronic package is a multi-layered structure that is consisted of several materials. Under the temperature loadings, the interfacial stresses between layered components are generated due to the CTE (coefficient of thermal expansion) mismatch between different materials. In die bonding process, the void or defect might exist at the die attach/die paddle interface. The void cause further delamination on the interface during the encapsulation process. In this study, the finite element method is used to construct the model of electronic package with a void on the die attach/die paddle interface. The energy release rate based on J integration, which is calculated by the stress and strain around the tip of crack, is used as a damage parameter to predict the tendency of further delamination during encapsulation. Effect of material properties (Young’s modulus and CTE) and die attach thickness on delamination of die attach/die paddle interface in package during encapsulation is studied.

Selective Rapid Thermal Chemical Vapor Deposition of Titanium Silicide on Arsenic Implanted Silicon

1998 ◽  
Vol 514 ◽  
Author(s):  
Hua Fang ◽  
Mehmet C. Özttirk ◽  
Edmund G. Seebauer
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Silicon Substrate ◽  
Chemical Vapor ◽  
Silicon Wafers ◽  
Titanium Silicide ◽  
Experimental Results ◽  
Substrate Consumption ◽  
Thermal Chemical Vapor Deposition ◽  
Dose Levels

ABSTRACTThis work explores the effects of arsenic on rapid thermal chemical vapor deposition (RTCVD) of TiSi2. The films were deposited using TiCI4 and SiH4 on 100 mm oxide patterned silicon wafers selectively at temperatures ranging from 750°C to 850°C. Arsenic dose levels ranging from 3×1014 cm−2 to 5*times;1015 cm−2 at 50 keV were considered. Experimental results reveal that arsenic results in a resistance to TiSi2 nucleation and enhanced silicon substrate consumption. These effects are enhanced at higher arsenic dose levels and reduced at higher deposition temperatures. We propose an arsenic-surfacepassivation model to explain the effects.

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