The Influence of Die-Attach Adhesives on the Packaging of MEMS Accelerometer

2015 ◽  
Vol 645-646 ◽  
pp. 533-537 ◽  
Author(s):  
Peng Peng ◽  
Xiao Ping He ◽  
Lian Ming Du ◽  
Wu Zhou ◽  
Hui Jun Yu ◽  
...  
Keyword(s):  
Thermal Coefficient ◽  
Adhesive Material ◽  
Accelerometer Sensor ◽  
Element Analysis ◽  
Mems Accelerometer ◽  
Capacitive Accelerometer ◽  
Die Attach ◽  
Stress And Deformation ◽  
Output Characteristics ◽  
Significant Factors

The attachment of the micromechanical silicon die to the substrate is one of the most critical steps in the packaging of highly accurate MEMS (microelectro-mechanical systems) accelerometer. The stress and strains, induced during die-attach process because of TCE (thermal coefficient of expansion) mismatches between different materials, will adversely affect the output characteristics of the accelerometer sensor. In this paper, three different materials: OE138, DG-3S and H70E are selected as the die-attach adhesives of a MEMS comb capacitive accelerometer. The stress and deformation of the silicon die, after the accelerometer model is cured from 80 °C to 20 °C, are evaluated with the aid of finite element analysis (FEA). As the results show, Young’s modulus and the thickness of the adhesives are the most significant factors influencing the stress and deformation of the silicon die. Soft adhesive material (OE138) have better stress absorption, and the stress and deformation of the silicon die decrease with the increasing thickness of the adhesive. Consequently, a soft and thick adhesive is recommended for the die-attach packaging of MEMS accelerometer.

A study of partial layout of adhesive on the thermal drift of MEMS capacitive accelerometers

2017 ◽  
Vol 31 (07) ◽  
pp. 1741006 ◽  
Author(s):  
Peng Peng ◽  
Wu Zhou ◽  
Huijun Yu ◽  
Qu Hao ◽  
Bei Peng ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Thermal Drift ◽  
Mems Devices ◽  
Element Analysis ◽  
Adhesive Bonds ◽  
Microelectromechanical System ◽  
Die Attachment ◽  
Capacitive Accelerometer ◽  
Stress And Deformation ◽  
Thermal Stability Of

The die attachment adhesive is commonly fully deposited on the substrate to connect the chips and the package shell in the packaging of microelectromechanical system (MEMS) devices. The packaging stress and deformation will be changed under temperature variation and further impact the thermal stability of devices. This paper describes a partial layout of die attachment adhesive used in a comb MEMS capacitive accelerometer, which can attenuate the thermal deformation and reduce the thermal drift of the sensor. The accelerometers with the bonded area designed from the global portion to nonsensitive portion of the sensor die are modeled by using finite element analysis (FEA) to study the deformation of the sensitive component induced by temperature change, and the corresponding thermal drift is obtained by simulation and theoretical methods. Both the results indicate that the thermal drift will decrease when the length of the unbonded area is larger than about 700 μm, and when the adhesive bonds only in the area of the nonsensitive portion of the sensor, the thermal drift will reduce about 19% relative to the global attachment. The partial layout of die attachment adhesive is therefore a useful method to improve the thermal stability for stress-sensitive MEMS devices.

scholarly journals Modeling of Leadframe Strip Warpage after Die Attach Cure Process

2021 ◽  
pp. 50-56
Author(s):  
Jefferson Talledo
Keyword(s):  
Stress Relief ◽  
Assembly Process ◽  
Lead Frame ◽  
Challenging Problem ◽  
Cure Process ◽  
Adhesive Material ◽  
Element Analysis ◽  
Die Attach ◽  
Actual Observation ◽  
Die Thickness

In the leadframe package assembly process, silicon die is attached to the leadframe using a die attach adhesive material and the bonded strip is then cured. However, excessive strip warpage after the die attach cure process is a challenging problem that also affects the succeeding assembly processes. In this study, strip warpage modeling was done using a finite element analysis (FEA) technique to understand the warpage mechanism after die attach cure and find options to reduce strip warpage. The effect of changing the leadframe thickness, die thickness, and the leadframe design in terms of the number of strip panels or changing the connecting bar was analyzed. Modeling demonstrated that lead frame contracts faster than the silicon die resulting in the “frowning” warpage that agrees with the actual observation. It was also shown that increasing the die thickness by 25% results in 27% warpage reduction. Results also showed that increasing the number of panels or maps in a strip could significantly reduce the strip warpage. Improving the panel-to-panel isolation using stress relief cuts is also another option to reduce warpage after die attach cure.

Method of Detecting Trace Metal Contamination in Thick-Film SOI Device

2005 ◽  
Author(s):  
Yasunori Goto ◽  
Hiroomi Eguchi ◽  
Masaru Iida
Keyword(s):  
Trace Metal ◽  
Thick Film ◽  
Metal Contamination ◽  
Semiconductor Device ◽  
Trace Element Analysis ◽  
Silicon On Insulator ◽  
Element Analysis ◽  
Trace Metal Contamination ◽  
Trace Metal Elements ◽  
Output Characteristics

Abstract In the automotive IC using thick-film silicon on insulator (SOI) semiconductor device, if the gettering capability of a SOI wafer is inadequate, electrical characteristics degradation by metal contamination arises and the yield falls. At this time, an automotive IC was made experimentally for evaluation of the gettering capability as one of the purposes. In this IC, one of the output characteristics varied from the standard, therefore failure analysis was performed, which found trace metal elements as one of the causes. By making full use of 3D perspective, it is possible to fabricate a site-specific sample into 0.1 micrometre in thickness without missing a failure point that has very minute quantities of contaminant in a semiconductor device. Using energy dispersive X-ray, it is possible to detect trace metal contamination at levels 1E12 atoms per sq cm. that are conventionally detected only by trace element analysis.

scholarly journals Calibration Analysis of High-G MEMS Accelerometer Sensor Based on Wavelet and Wavelet Packet Denoising

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1231
Author(s):  
Yunbo Shi ◽  
Juanjuan Zhang ◽  
Jingjing Jiao ◽  
Rui Zhao ◽  
Huiliang Cao
Keyword(s):  
Wavelet Packet ◽  
Estimation Method ◽  
Likelihood Estimation ◽  
Parameter Extraction ◽  
Accelerometer Sensor ◽  
Oscillation Phase ◽  
Mems Accelerometer ◽  
Optimal Tree ◽  
Adaptive Decomposition ◽  
Entropy Criterion

High-G accelerometers are mainly used for motion measurement in some special fields, such as projectile penetration and aerospace equipment. This paper mainly explores the wavelet threshold denoising and wavelet packet threshold denoising in wavelet analysis, which is more suitable for high-G piezoresistive accelerometers. In this paper, adaptive decomposition and Shannon entropy criterion are used to find the optimal decomposition layer and optimal tree. Both methods use the Stein unbiased likelihood estimation method for soft threshold denoising. Through numerical simulation and Machete hammer test, the wavelet threshold denoising is more suitable for the dynamic calibration of a high-G accelerometer. The wavelet packet threshold denoising is more suitable for the parameter extraction of the oscillation phase.

Construction Monitoring on Steel Truss Bridge’s Maintenance and Reinforcement

2018 ◽  
Vol 878 ◽  
pp. 89-94 ◽  
Author(s):  
Er Lei Wang
Keyword(s):  
Simulation Analysis ◽  
Analysis Model ◽  
Element Analysis ◽  
Construction Monitoring ◽  
Finite Element Analysis Model ◽  
Bridge Steel ◽  
Steel Truss ◽  
Stress And Deformation ◽  
Site Test

Implementing monitoring over construction process of old bridge’s reinforcement serves as an important measure to ensure construction quality and safety and realize the goal of reinforcement. This paper, with a case study of the maintenance and reinforcement project of Zhicheng Yangtze River Bridge (steel truss highway-railway combined bridge), adopted MIDAS to establish finite element analysis model, and with stress and deformation as monitoring parameters, completed the construction monitoring work, numerical simulation analysis and site test for the reinforcement project.

scholarly journals The Effect of Nanoparticles in Single Lap Joints Studied by Numerical Analyses

2020 ◽  
Vol 5 (10) ◽  
pp. 1288-1293
Author(s):  
Panagiotis J. Charitidis
Keyword(s):  
Finite Element ◽  
Failure Load ◽  
Tensile Loading ◽  
Lap Joints ◽  
Von Mises Stress ◽  
Adhesive Material ◽  
Element Analysis ◽  
Single Lap Joints ◽  
Epoxy Adhesives ◽  
Von Mises

The present study concerns with the finite element investigation of balanced aluminium single lap joints subjected to tensile loading. Epoxy adhesives were used for bonding having different nanoparticles rate in the epoxy resin (0.5, 1.0, 1.5 and to 2 wt. %, respectively). Two-dimensional (2D) finite element analysis has been employed to determine the peeling stress, von Mises stress, and the shear strain distribution across the midplane of the joints. The results mainly prove that the nanoparticles rate in the adhesive material directly affects the joint tensile strength. Nanocomposite adhesives present a higher failure load than that of neat adhesives. Furthermore, nanocomposite adhesive with 0.5 wt. % of nanoparticles generated strengths (shear and peeling strengths) more than neat adhesives, after which decreased by further addition of the nanoparticles.

scholarly journals Investigation on Die Crack in a Stacked Die Package Using Finite Element Analysis

2021 ◽  
pp. 83-91
Author(s):  
Jefferson Talledo
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Coefficient Of Thermal Expansion ◽  
Crack Problem ◽  
Element Analysis ◽  
Robust Solution ◽  
Die Attach ◽  
Die Stress ◽  
Cte Mismatch ◽  
Semiconductor Packages

Die crack is one of the problems in stacked die semiconductor packages. As silicon dies become thinner in such packages due to miniaturization requirement, the tendency to have die crack increases. This study presents the investigation done on a die crack issue in a stacked die package using finite element analysis (FEA). The die stress induced during the package assembly processes from die attach to package strip reflow was analyzed and compared with the actual die crack failure in terms of the location of maximum die stress at unit level as well as strip level. Stresses in the die due to coefficient of thermal expansion (CTE) mismatch of the package component materials and mechanical bending of the package in strip format were taken into consideration. Comparison of the die stress with actual die crack pointed to strip bending as the cause of the problem and not CTE mismatch. It was found that the die crack was not due to the thermal processes involved during package assembly. This study showed that analyzing die stress using FEA could help identify the root cause of a die crack problem during the stacked die package assembly and manufacturing as crack occurs at locations of maximum stress. The die crack mechanism can also be understood through FEA simulation and such understanding is very important in coming up with robust solution.

Thermal and Mechanical Characterization of High Power GaN Packages

2011 ◽  
Vol 2011 (1) ◽  
pp. 000361-000366
Author(s):  
Don Willis ◽  
Gary Gu ◽  
Daniel Jin ◽  
Rob Dry
Keyword(s):  
Thermal Performance ◽  
High Power ◽  
Mechanical Analysis ◽  
Heat Spreader ◽  
Element Analysis ◽  
Die Attach ◽  
Viable Solution ◽  
Alternative Approach ◽  
Thermal Improvement ◽  
Multiple Devices

The typical package available for high power GaN application has the devices directly attached onto a metal flange, which could contribute significantly to the overall thermal resistance. This paper discusses an alternative approach to packaging both single and multiple devices through a heat spreader, which could potentially improve thermal performance and bring significant benefits to assembly in yields and cost. However, the heat spreader could also introduce significant CTE mis-match and potential concerns in reliability. Nonlinear 3D finite element analysis (FEA) was conducted to characterize the thermal performance and evaluate mechanical/reliability concerns. Thermal modeling considered single and multiple die applications, and the results show13–15% thermal improvement with the copper heat spreader. Mechanical analysis focused on the thermal loads of the die attach and solder reflow processes. It reveals that the die attach process is more critical as shown in the higher stress due to higher thermal load, but stress/strain levels appear to be acceptable. Thus, this alternative approach could be a viable solution.

FORCE CHARACTERIZATION OF A TUBULAR LINEAR ELECTROMAGNETIC ACTUATOR USING FINITE ELEMENT ANALYSIS METHOD (FEM)

2016 ◽  
Vol 78 (11) ◽  
Author(s):  
Mariam Md Ghazaly ◽  
Tawfik Ahmed Yahya ◽  
Aliza Che Amran ◽  
Zulkeflee Abdullah ◽  
Mohd Amran Md Ali ◽  
...  
Keyword(s):  
Finite Element ◽  
Ansys Software ◽  
Element Analysis ◽  
Electromagnetic Actuators ◽  
Halbach Array ◽  
Output Characteristics ◽  
Actuator Design ◽  
Force Displacement ◽  
The Magnetic Field

This paper presents an extensive characterising study of two novel electromagnetic actuators, each with different constructions and characteristics aiming to analyse the behaviour and output characteristics of the two designs. The two actuators are Tubular Linear Reluctance Actuator (TLRA) and Tubular Linear Permanent magnet (TLPM) with Halbach array actuator. The study covered the variation of three parameters, which are the actuator air gap, number of turns and actuator size. A comparative section was also presented for the purpose of comparison. The study concentrated extensively on the two characteristics of both actuators known as output thrust force and working range as they are considered as two main concerns of any actuator design. The simulation was used to show the differences between the two designs in many design aspects such as force, displacement and effects of parameters variations. The applied simulation was performed using 3D Finite-element Ansys software, which is capable of showing the magnetic field distribution in the whole actuator and predicting the strength and length of the output stroke.

Sign in / Sign up

Export Citation Format

Share Document