scholarly journals Research on Wafer-Level MEMS Packaging with Through-Glass Vias

Micromachines ◽  
2018 ◽  
Vol 10 (1) ◽  
pp. 15 ◽  
Author(s):  
Fan Yang ◽  
Guowei Han ◽  
Jian Yang ◽  
Meng Zhang ◽  
Jin Ning ◽  
...  
Keyword(s):  
Low Cost ◽  
Picosecond Laser ◽  
Drilling Process ◽  
Wafer Level ◽  
Mems Packaging ◽  
Vacuum Degree ◽  
Mems Fabrication ◽  
Via Holes ◽  
Silicon Structures ◽  
Made In

A MEMS fabrication process with through-glass vias (TGVs) by laser drilling was presented, and reliability concerns about MEMS packaging with TGV, likes debris and via metallization, were overcome. The via drilling process on Pyrex 7740 glasses was studied using a picosecond laser with a wavelength of 532 nm. TGVs were tapered, the minimum inlet diameter of via holes on 300 μm glasses was 90 μm, and the relative outlet diameter is 48 μm. It took about 9 h and 58 min for drilling 4874 via holes on a four-inch wafer. Debris in ablation was collected only on the laser inlet side, and the outlet side was clean enough for bonding. The glass with TGVs was anodically bonded to silicon structures of MEMS sensors for packaging, electron beam evaporated metal was used to cover the bottom, the side, and the surface of via holes for vertical electrical interconnections. The metal was directly contacted to silicon with low contact resistance. A MEMS gyroscope was made in this way, and the getter was used for vacuum maintenance. The vacuum degree maintained under 1 Pa for more than two years. The proposed MEMS fabrication flow with a simple process and low cost is very suitable for mass production in industry.

scholarly journals Bimetallic Ni-Based Catalysts for CO2 Methanation: A Review

Nanomaterials ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 28
Author(s):  
Anastasios I. Tsiotsias ◽  
Nikolaos D. Charisiou ◽  
Ioannis V. Yentekakis ◽  
Maria A. Goula
Keyword(s):  
Low Temperature ◽  
Noble Metals ◽  
Recent Progress ◽  
Low Cost ◽  
Alloy Formation ◽  
Co2 Methanation ◽  
High Performing ◽  
Mobile Sources ◽  
Low Dispersion ◽  
Made In

CO2 methanation has recently emerged as a process that targets the reduction in anthropogenic CO2 emissions, via the conversion of CO2 captured from point and mobile sources, as well as H2 produced from renewables into CH4. Ni, among the early transition metals, as well as Ru and Rh, among the noble metals, have been known to be among the most active methanation catalysts, with Ni being favoured due to its low cost and high natural abundance. However, insufficient low-temperature activity, low dispersion and reducibility, as well as nanoparticle sintering are some of the main drawbacks when using Ni-based catalysts. Such problems can be partly overcome via the introduction of a second transition metal (e.g., Fe, Co) or a noble metal (e.g., Ru, Rh, Pt, Pd and Re) in Ni-based catalysts. Through Ni-M alloy formation, or the intricate synergy between two adjacent metallic phases, new high-performing and low-cost methanation catalysts can be obtained. This review summarizes and critically discusses recent progress made in the field of bimetallic Ni-M (M = Fe, Co, Cu, Ru, Rh, Pt, Pd, Re)-based catalyst development for the CO2 methanation reaction.

InSb Czochralski Growth Single Crystals for InGaSb Substrates

2014 ◽  
Vol 1616 ◽  
Author(s):  
J. E. Flores Mena ◽  
R. Castillo Ojeda ◽  
J. Díaz Reyes
Keyword(s):  
Low Cost ◽  
Electronic Devices ◽  
Czochralski Method ◽  
Liquid Nitrogen Temperature ◽  
Longitudinal Optical ◽  
Czochralski Growth ◽  
Etch Pit ◽  
Growth System ◽  
Radiation Sensors ◽  
Made In

ABSTRACTThe massive crystal growth of single crystal semiconductors materials has been of fundamental importance for the actual electronic devices industry. As a consequence of this one, we can obtain easily a large variety of low cost devices almost as made ones of silicon. Nowadays, the III-V semiconductors compounds and their alloys have been proved to be very important because of their optical properties and applications. It is the case of the elements In, Ga, As, Sb, which can be utilized for the fabrication of radiation sensors. In this work we present the results obtained from the ingots grown by the Czochralski method, using a growth system made in home. These results include anisotropic chemical attacks in order to reveal the crystallographic orientation and the possible polycrystallinity. Isotropic chemical attacks were made to evaluate the etch pit density. Metallographic pictures of the chemical attacks are presented in this work. Among the results of these measurements, the best samples presented in this work showed mobilities of 62.000 cm2/V*s at room temperature and 99.000 cm2/V*s at liquid nitrogen temperature. Typical pit density was 10,000/cm2. The Raman spectra present two dominant peaks associated at Transversal Optical (TO)- and Longitudinal Optical (LO)-InSb, the first vibrational mode is dominant due to the crystalline direction of the ingots and second one is associated to high defects density.

scholarly journals Extraction of γ-Alumina from Low-Cost Kaolin

Resources ◽  
2018 ◽  
Vol 7 (4) ◽  
pp. 63
Author(s):  
Khalil Ibrahim ◽  
Mohammad Moumani ◽  
Salsabeela Mohammad
Keyword(s):  
Low Cost ◽  
Morphological Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Aluminum Metal ◽  
Alumina Particles ◽  
Two Stages ◽  
Method Of Extraction ◽  
Microcrystalline Powder ◽  
Made In

A combined process is proposed for the utilization of local kaolin to produce alumina particles. The applied process is made in two stages: calcination at 700 °C with sodium chloride and leaching with sulfuric followed by hydrochloric acids. The optimal extraction efficiency can be obtained when the conditions are as follows: leaching temperature is at 140 °C, leaching time is 3 h 45 min and concentration of sulfuric acid is 40 wt.%. The results show that the purity of alumina reaches 79.28%, which is suitable for the production of aluminum metal. It is evident that this method of extraction of alumina from the kaolin ash is practical and feasible. The structural and morphological properties of the calcined microcrystalline powder was characterized by X-ray diffraction and scanning electron microscope (SEM).

scholarly journals A secondary stage design for the preparation of microfossils for the SEM

1993 ◽  
Vol 12 (2) ◽  
pp. 154-154
Author(s):  
Stephen Tatman
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Low Cost ◽  
Sample Tube ◽  
Stage Design ◽  
Single Carrier ◽  
Secondary Stage ◽  
Scanning Electron ◽  
Made In

Abstract. The preparation of microfossil specimens for study with the scanning electron microscope involves the transfer of material from slides to stubs. Specimens must then be oriented and mounted securely. To do this accurately the slide and stub should both be viewed through a stereomicroscope. However due to differences in shape and height, both surfaces are not usually in the plane of focus at the same time. Many micropalaeontologists routinely use small boxes or sample tube lids to hold the stub and refocus before finally mounting the specimens. The risk of dropping specimens is reduced by using a single carrier, securely holding both the slide and stub. The design illustrated below (fig.1) was developed from a prototype constructed from cardboard and plastic. The metal unit can easily be made in a workshop at a very low cost or cardboard versions made in the laboratory.The stage is based on the principle that both slide and stub should be held securely, close together and in the same plane of focus. The slide holders should be secure but not too tight otherwise the stub may be jarred as slides are changed. The number of slides which can be held on one unit may be varied. The presence of two holders has proved useful, any more could make the unit cumbersome. If the microscope to be used does not have a wide stage then it may prove more practical to have only one holder.The stub holders allow the stub to be clamped to . . .

scholarly journals Photogrammetry-based Texture Analysis of a Volcaniclastic Outcrop-peel: Low-cost Alternative to TLS and Automation Potentialities using Haar Wavelet and Spatial-Analysis Algorithms

2017 ◽  
Vol 31 (1) ◽  
pp. 16-27 ◽  
Author(s):  
Christopher Gomez ◽  
Kyoko Kataoka ◽  
Aditya Saputra ◽  
Patrick Wassmer ◽  
Atsushi Urabe ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Wavelet Decomposition ◽  
Low Cost ◽  
Decomposition Analysis ◽  
Haar Wavelet ◽  
Present Contribution ◽  
Close Range Photogrammetry ◽  
Original Goal ◽  
Close Range ◽  
Made In

Numerous progress has been made in the field of applied photogrammetry in the last decade, including the usage of close-range photogrammetry as a mean of conservation and record of outcrops. In the present contribution, we use the SfM-MVS method combined with a wavelet decomposition analysis of the surface, in order to relate it to morphological and surface roughness data. The results demonstrated that wavelet decomposition and RMS could provide a rapid insight on the location of coarser materials and individual outliers, while arithmetic surface roughness were more useful to detect units or layers that are similar on the outcrop. The method also emphasizes the fact that the automation of the process does not allows clear distinction between any artefact crack or surface change and that human supervision is still essential despite the original goal of automating the outcrop surface analysis.

scholarly journals The Rise of the OM-LoC: Opto-Microfluidic Enabled Lab-on-Chip

Micromachines ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1467
Author(s):  
Harry Dawson ◽  
Jinane Elias ◽  
Pascal Etienne ◽  
Sylvie Calas-Etienne
Keyword(s):  
Low Cost ◽  
Optical Components ◽  
New Era ◽  
Lab On Chip ◽  
Highly Sensitive ◽  
Multiple Challenges ◽  
On Chip ◽  
Optical Circuits ◽  
Made In

The integration of optical circuits with microfluidic lab-on-chip (LoC) devices has resulted in a new era of potential in terms of both sample manipulation and detection at the micro-scale. On-chip optical components increase both control and analytical capabilities while reducing reliance on expensive laboratory photonic equipment that has limited microfluidic development. Notably, in-situ LoC devices for bio-chemical applications such as diagnostics and environmental monitoring could provide great value as low-cost, portable and highly sensitive systems. Multiple challenges remain however due to the complexity involved with combining photonics with micro-fabricated systems. Here, we aim to highlight the progress that optical on-chip systems have made in recent years regarding the main LoC applications: (1) sample manipulation and (2) detection. At the same time, we aim to address the constraints that limit industrial scaling of this technology. Through evaluating various fabrication methods, material choices and novel approaches of optic and fluidic integration, we aim to illustrate how optic-enabled LoC approaches are providing new possibilities for both sample analysis and manipulation.

scholarly journals Advanced Strategies to Improve Performances of Molybdenum-Based Gas Sensors

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Angga Hermawan ◽  
Ni Luh Wulan Septiani ◽  
Ardiansyah Taufik ◽  
Brian Yuliarto ◽  
Suyatman ◽  
...  
Keyword(s):  
High Performance ◽  
Gas Sensing ◽  
Low Cost ◽  
Molybdenum Oxides ◽  
Exhaled Breath ◽  
Sensor Applications ◽  
Theoretical Investigations ◽  
Gas Sensing Properties ◽  
Future Challenges ◽  
Made In

AbstractMolybdenum-based materials have been intensively investigated for high-performance gas sensor applications. Particularly, molybdenum oxides and dichalcogenides nanostructures have been widely examined due to their tunable structural and physicochemical properties that meet sensor requirements. These materials have good durability, are naturally abundant, low cost, and have facile preparation, allowing scalable fabrication to fulfill the growing demand of susceptible sensor devices. Significant advances have been made in recent decades to design and fabricate various molybdenum oxides- and dichalcogenides-based sensing materials, though it is still challenging to achieve high performances. Therefore, many experimental and theoretical investigations have been devoted to exploring suitable approaches which can significantly enhance their gas sensing properties. This review comprehensively examines recent advanced strategies to improve the nanostructured molybdenum-based material performance for detecting harmful pollutants, dangerous gases, or even exhaled breath monitoring. The summary and future challenges to advance their gas sensing performances will also be presented.

Making and Trading Dress and Décor in Seventeenth-century Scotland

2021 ◽  
Vol 100 (3) ◽  
pp. 419-436
Author(s):  
T. C. Smout
Keyword(s):  
Seventeenth Century ◽  
Comparative Advantage ◽  
Low Cost ◽  
Wide Distribution ◽  
Economic Stress ◽  
Textile Production ◽  
Limited Impact ◽  
The Social ◽  
Rural Wages ◽  
Made In

In seventeenth-century Scotland textiles were made in most districts and marketed widely at home and overseas. Woollens and linens, yarn, cloth, bonnets and stockings, with clear regional specialisations, were manufactured, but they were all of low cost and quality. Comparative advantage came from low rural wages. The wide distribution and character of textile production in the seventeenth century proved of great importance for post-Union success. Among imports the variety and social spread of luxury widened and deepened, though demand was restricted to the upper classes and the middling orders in Edinburgh and other large burghs. The seventeenth century, especially the second half, was a time of widening consumption of exotic articles such as tobacco, sugar and coffee among consumables, Asian silks and cottons (and their imitations) as articles of dress, and wall-hangings and pictures as décor. The social anxiety and economic stress this engendered gave rise to sumptuary laws like that of 1681. These had limited impact, though imports remained sensitive to tariffs. The letters of Andrew Russell, a merchant resident in Rotterdam between 1668 and 1697, demonstrate how this trade was carried out in both directions, and how the market responded to governmental attempts at control.

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