scholarly journals Impact of Die Attach Sample Preparation on Its Measured Mechanical Properties for MEMS Sensor Applications

2021 ◽  
Vol 18 (1) ◽  
pp. 21-28
Author(s):  
Abel Misrak ◽  
Tushar Chauhan ◽  
Rabin Bhandari ◽  
A S M Raufur Chowdhury ◽  
Akshay Lakshminarayana ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Sample Preparation ◽  
Computational Modeling ◽  
Material Characterization ◽  
Computational Models ◽  
Preparation Technique ◽  
Sensor Applications ◽  
Sensor Performance ◽  
Mems Sensor ◽  
Die Attach

Abstract Computational modeling is often leveraged to design and optimize electronic packages for both performance and reliability purposes. One of the factors that affect the accuracy of computational models is the accuracy of the material properties. Microelectromechanical system sensors, in particular, are usually extremely sensitive to slightest material property changes in the package. Therefore, even small measurement variations in material characterization due to different sample preparation methods or different testing techniques can impact accuracy of computational models that are leveraged for designing or analyzing sensor performance. The challenge in material characterization is even greater for materials that require curing. Die attach polymers, for example, have strict curing profile requirements that are used during the manufacturing process. Such curing conditions are usually hard to duplicate in laboratories, and the samples used for material characterization may not necessarily be representative of the actual component in the final product. In this study, the effect of parameters such as temperature curing profile, application of pressure during curing, and sample preparation technique on temperature-dependent thermomechanical properties of two types of die attach elastomers is investigated. The mechanical properties, including the elastic modulus (E), coefficient of thermal expansion, and glass transition temperature of the die attach material, are measured using a suite of techniques such as dynamic mechanical analysis and thermomechanical analysis. The analysis is performed for a wide temperature range corresponding to typical sensor applications. It is shown that sample preparation and characterization techniques have a considerable impact on the measurements, which results in different MEMS sensor performance predictions through computational modeling.

Three-Dimensional Modeling of Reduced Material Properties in Ceramics With Added Porosity

2019 ◽  
Author(s):  
Stephanie A. Wimmer ◽  
Virginia G. DeGiorgi ◽  
Edward P. Gorzkowski ◽  
Heonjune Ryou
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Finite Element ◽  
Computational Modeling ◽  
Computational Models ◽  
Thermal Protection ◽  
Turbine Blades ◽  
Three Dimensional ◽  
Ceramic Coatings ◽  
Grain Structure

Abstract Manufacturing methods to create ceramic coatings with tailored thermal conductivity are crucial to the development of thermal protection systems for many components including turbine blades in high temperature engines. A designed microstructure of grains, pores, and other defects can reduce the thermal conductivity of the ceramic. However, the same microstructure characteristics can reduce mechanical properties to the point of failure. This work is part of a larger program with the goal of optimizing ceramic coating microstructure for thermal protection while retaining sufficient mechanical strength for the intended application. Processing parameters have been examined to identify methods designed to maintain a nano-sized grain structure of yttria-stabilized zirconia while controlling the added porosity with a specific shape and size. In this paper computational modeling is used to evaluate the effects of porosity on coating performance, both thermal and structural. Coating porosity is incorporated in the computational models by randomly placing empty spaces or defects in the shape of spherical voids, oblate pores, or penny cracks. In addition to computational modeling, prototype coatings are developed in the laboratory with specific porosity. The size and orientation of defects in the computational modeling effort are statistically generated to match experiments. The locations of the defects are totally random. Finite element models are created which include various levels of porosity to calculate effective thermal and mechanical properties. Comparisons are made between three-dimensional finite-element simulations and measured data. The influences of pore size as well as three dimensional computational modeling artifacts are examined.

A User’s Perspective: Packaging Achieves Test Affordability

2000 ◽  
Author(s):  
Wayne P. Liu
Keyword(s):  
Stress Testing ◽  
Impact Test ◽  
Separation Bubble ◽  
Hardware Cost ◽  
Good Data ◽  
Sensor Applications ◽  
Sensor Performance ◽  
Mems Sensor ◽  
Set Up ◽  
The Cost

Abstract Sensor performance and cost are typically the main features reviewed by potential users of MEMS sensor applications. However with more options becoming available, experienced users will begin to consider more than just performance and hardware cost and will seek packaging features which reduce the effort needed to set up, calibrate and successfully operate MEMS sensor systems. A reduction in the cost of effort needed to collect good data will impact test affordability. Data from MEMS shear stress testing on cylinder boundary layer and separation bubble features will be presented to show how packaging can affect both performance and affordability. Manufacturers should ask: What is remembered the most at the conclusion of a MEMS application, the cost of hardware or the cost of effort required to collect good data?

scholarly journals Development of Co(OH)xF2−x Nanosheets for Acetone Gas Sensor Applications: Material Characterization and Sensor Performance Evaluation

Crystals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 968
Author(s):  
Yaping Yan ◽  
Tae-yil Eom ◽  
Shiyu Xu ◽  
Pil J. Yoo ◽  
Changzeng Yan ◽  
...  
Keyword(s):  
Gas Sensor ◽  
Material Characterization ◽  
High Specific Surface Area ◽  
High Concentration ◽  
Hydrothermal Route ◽  
Sensor Applications ◽  
Sensor Performance ◽  
Operation Temperature ◽  
Catalytic Function ◽  
New Material

This study reports the employment of Co(OH)xF2−x nanosheets, a new material in the sensor field, for gas sensor applications. We synthesize Co(OH)xF2−x nanosheets via a hydrothermal route using SiO2 sphere templates. Our material characterization confirms that the material is a densely clustered Co(OH)xF2−x nanosheet with an amorphous microstructure with some short-range ordering. Sensors based on the nanosheets demonstrate a high response of 269% toward 4.5 ppm of acetone gas at an operation temperature of 200 °C and a very low minimum detection limit of 40 ppb. It functions effectively up to a temperature below 300 °C, above which F is found to start to evaporate. Our discussion suggests that an excellent sensor performance arises from the high catalytic function of F incorporated in a high concentration in the material as well as the high specific surface area due to the morphology of densely clustered nanosheets.

SEM evaluation of the TEM cold-stage double-film specimen

1984 ◽  
Vol 42 ◽  
pp. 272-273
Author(s):  
Jayesh Bellare
Keyword(s):  
Spatial Distribution ◽  
Sample Preparation ◽  
Sample Thickness ◽  
Specimen Preparation ◽  
Preparation Technique ◽  
Liquid Sample ◽  
Thin Specimen ◽  
Sample Preparation Technique ◽  
Cold Stage ◽  
Film Specimen

Seeing is believing, but only after the sample preparation technique has received a systematic study and a full record is made of the treatment the sample gets.For microstructured liquids and suspensions, fast-freeze thermal fixation and cold-stage microscopy is perhaps the least artifact-laden technique. In the double-film specimen preparation technique, a layer of liquid sample is trapped between 100- and 400-mesh polymer (polyimide, PI) coated grids. Blotting against filter paper drains excess liquid and provides a thin specimen, which is fast-frozen by plunging into liquid nitrogen. This frozen sandwich (Fig. 1) is mounted in a cooling holder and viewed in TEM.Though extremely promising for visualization of liquid microstructures, this double-film technique suffers from a) ireproducibility and nonuniformity of sample thickness, b) low yield of imageable grid squares and c) nonuniform spatial distribution of particulates, which results in fewer being imaged.

A technique for preparing semiconductor cross sections for both TEM and SEM analysis

1989 ◽  
Vol 47 ◽  
pp. 712-713
Author(s):  
Stanley J. Klepeis ◽  
J.P. Benedict ◽  
R.M Anderson
Keyword(s):  
Sample Preparation ◽  
Cross Section ◽  
Cross Sections ◽  
Sem Analysis ◽  
Preparation Technique ◽  
Ion Milling ◽  
Tem Analysis ◽  
Polished Cross Section ◽  
Area Of Interest ◽  
Polished Side

The ability to prepare a cross-section of a specific semiconductor structure for both SEM and TEM analysis is vital in characterizing the smaller, more complex devices that are now being designed and manufactured. In the past, a unique sample was prepared for either SEM or TEM analysis of a structure. In choosing to do SEM, valuable and unique information was lost to TEM analysis. An alternative, the SEM examination of thinned TEM samples, was frequently made difficult by topographical artifacts introduced by mechanical polishing and lengthy ion-milling. Thus, the need to produce a TEM sample from a unique,cross-sectioned SEM sample has produced this sample preparation technique.The technique is divided into an SEM and a TEM sample preparation phase. The first four steps in the SEM phase: bulk reduction, cleaning, gluing and trimming produces a reinforced sample with the area of interest in the center of the sample. This sample is then mounted on a special SEM stud. The stud is inserted into an L-shaped holder and this holder is attached to the Klepeis polisher (see figs. 1 and 2). An SEM cross-section of the sample is then prepared by mechanically polishing the sample to the area of interest using the Klepeis polisher. The polished cross-section is cleaned and the SEM stud with the attached sample, is removed from the L-shaped holder. The stud is then inserted into the ion-miller and the sample is briefly milled (less than 2 minutes) on the polished side. The sample on the stud may then be carbon coated and placed in the SEM for analysis.

TEM sample preparation of wear-tested room-temperature pulsed-laser-deposited thin films of MoS2 by ultramicrotomy

1993 ◽  
Vol 51 ◽  
pp. 1118-1119
Author(s):  
Pamela F. Lloyd ◽  
Scott D. Walck
Keyword(s):  
Thin Films ◽  
Sample Preparation ◽  
Room Temperature ◽  
High Vacuum ◽  
Pulsed Laser ◽  
Ultra High Vacuum ◽  
Wear Testing ◽  
Preparation Technique ◽  
Cross Sectional ◽  
Aerospace Applications

Pulsed laser deposition (PLD) is a novel technique for the deposition of tribological thin films. MoS2 is the archetypical solid lubricant material for aerospace applications. It provides a low coefficient of friction from cryogenic temperatures to about 350°C and can be used in ultra high vacuum environments. The TEM is ideally suited for studying the microstructural and tribo-chemical changes that occur during wear. The normal cross sectional TEM sample preparation method does not work well because the material’s lubricity causes the sandwich to separate. Walck et al. deposited MoS2 through a mesh mask which gave suitable results for as-deposited films, but the discontinuous nature of the film is unsuitable for wear-testing. To investigate wear-tested, room temperature (RT) PLD MoS2 films, the sample preparation technique of Heuer and Howitt was adapted.Two 300 run thick films were deposited on single crystal NaCl substrates. One was wear-tested on a ball-on-disk tribometer using a 30 gm load at 150 rpm for one minute, and subsequently coated with a heavy layer of evaporated gold.

Introduction of a Novel Sample Preparation Technique for the Failure Analysis of Silicon Integrated Photonics Modules

2019 ◽  
Author(s):  
Pradip Sairam Pichumani ◽  
Fauzia Khatkhatay
Keyword(s):  
Sample Preparation ◽  
Failure Analysis ◽  
Silicon Photonics ◽  
Cmos Technology ◽  
Single Step ◽  
Oxide Semiconductor ◽  
Disruptive Technology ◽  
Preparation Technique ◽  
Test Vehicle ◽  
Sample Preparation Technique

Abstract Silicon photonics is a disruptive technology that aims for monolithic integration of photonic devices onto the complementary metal-oxide-semiconductor (CMOS) technology platform to enable low-cost high-volume manufacturing. Since the technology is still in the research and development phase, failure analysis plays an important role in determining the root cause of failures seen in test vehicle silicon photonics modules. The fragile nature of the test vehicle modules warrants the development of new sample preparation methods to facilitate subsequent non-destructive and destructive analysis methods. This work provides an example of a single step sample preparation technique that will reduce the turnaround time while simultaneously increasing the scope of analysis techniques.

Metallic Nanoneedles Arrays for TEM Sample Preparation “Lift-Out”

2012 ◽  
Author(s):  
Romaneh Jalilian ◽  
David Mudd ◽  
Neil Torrez ◽  
Jose Rivera ◽  
Mehdi M. Yazdanpanah ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Electron Microscope ◽  
Sample Preparation ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Beam System ◽  
Transmission Electron ◽  
Nanoneedle Array ◽  
Superior Mechanical Properties ◽  
And Performance

Abstract The sample preparation for transmission electron microscope can be done using a method known as "lift-out". This paper demonstrates a method of using a silver-gallium nanoneedle array for a quicker sharpening process of tungsten probes with better sample viewing, covering the fabrication steps and performance of needle-tipped probes for lift-out process. First, an array of high aspect ratio silver-gallium nanoneedles was fabricated and coated to improve their conductivity and strength. Then, the nanoneedles were welded to a regular tungsten probe in the focused ion beam system at the desired angle, and used as a sharp probe for lift-out. The paper demonstrates the superior mechanical properties of crystalline silver-gallium metallic nanoneedles. Finally, a weldless lift-out process is described whereby a nano-fork gripper was fabricated by attaching two nanoneedles to a tungsten probe.

A Modified QuEChERS Extraction and LC-MS/MS Method for the Determination of Pesticide Residues in Curry Leaves (Murraya koenigii)

2019 ◽  
Vol 6 (1) ◽  
pp. 30-41
Author(s):  
Ranjith Arimboor ◽  
Karunkara Ramakrishna Menon ◽  
Natarajan Ramesh Babu ◽  
Haneesh Chandran
Keyword(s):  
Sample Preparation ◽  
Matrix Effect ◽  
Retention Time ◽  
Pesticide Residues ◽  
Mobile Phase ◽  
Preparation Technique ◽  
Modified Quechers ◽  
Curry Leaves ◽  
Ms Analysis ◽  
The Matrix

Background:Increased consumer demand for curry leaves free from pesticides demands fast and reliable analytical methods for the analysis of pesticide residues.Objective:The optimization of a QuEChERS based sample preparation technique with improved analytical accuracy by removing interfering matrix components for LC-MS/MS analysis of pesticide residues from curry leaves.Methods:A modified QuEChERS solid phase extraction method was developed and validated for the analysis of 26 pesticides in fresh and dried curry leaves. The effects of the sample preparation steps and column retention time on the matrix suppression of analyte ions were also evaluated.Results:Validation parameters were found within an acceptable range. The matrix effect evaluation studies showed that the QuEChERS sample preparation was able to minimize the ion suppression of analytes due to co-eluting matrix of components and that a d-SPE clean up step had major role in reducing matrix effect. The gradient mobile phase with longer retention time for analytes resulted in comparatively lesser matrix effects than the isocratic mobile phase of non-polar nature. Even after the clean up, a considerable number of compounds had more than 20% reduction in their MS response in the gradient mobile phase.Conclusion:This study emphasized the need of proper sample clean up before a LC-MS/MS analysis and the usage of matrix matched standards and mobile phase that ultimately results in an appropriate analyte separation in reasonable retention times.

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