New low-cost high vacuum laboratory system

Vacuum ◽  
1994 ◽  
Vol 45 (1) ◽  
pp. 153
Keyword(s):  
Low Cost ◽  
High Vacuum ◽  
Laboratory System

scholarly journals Preparation of InSe Thin Films by Thermal Evaporation Method and Their Characterization: Structural, Optical, and Thermoelectrical Properties

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Sarita Boolchandani ◽  
Subodh Srivastava ◽  
Y. K. Vijay
Keyword(s):  
Thin Films ◽  
Seebeck Coefficient ◽  
Thermoelectric Power ◽  
Temperature Variation ◽  
Thermal Evaporation ◽  
Low Cost ◽  
High Vacuum ◽  
Power Measurement ◽  
Thermal Evaporation Method ◽  
Evaporation Method

The indium selenium (InSe) bilayer thin films of various thickness ratios, InxSe(1-x) (x = 0.25, 0.50, 0.75), were deposited on a glass substrate keeping overall the same thickness of 2500 Ǻ using thermal evaporation method under high vacuum atmosphere. Electrical, optical, and structural properties of these bilayer thin films have been compared before and after thermal annealing at different temperatures. The structural and morphological characterization was done using XRD and SEM, respectively. The optical bandgap of these thin films has been calculated by Tauc’s relation that varies within the range of 1.99 to 2.05 eV. A simple low-cost thermoelectrical power measurement setup is designed which can measure the Seebeck coefficient “S” in the vacuum with temperature variation. The setup temperature variation is up to 70°C. This setup contains a Peltier device TEC1-12715 which is kept between two copper plates that act as a reference metal. Also, in the present work, the thermoelectric power of indium selenide (InSe) and aluminum selenide (AlSe) bilayer thin films prepared and annealed in the same way is calculated. The thermoelectric power has been measured by estimating the Seebeck coefficient for InSe and AlSe bilayer thin films. It was observed that the Seebeck coefficient is negative for InSe and AlSe thin films.

The Production of Reduced Graphene Oxide by a Low-Cost Vacuum System for Supercapacitor Applications

2018 ◽  
Vol 930 ◽  
pp. 609-612
Author(s):  
Quezia Cardoso ◽  
Franks Martins Silva ◽  
Ligia Silverio Vieira ◽  
Julio Cesar Serafim Casini ◽  
Solange Kazume Sakata ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Large Scale ◽  
Low Cost ◽  
High Vacuum ◽  
Cost Effective ◽  
Practical Method ◽  
Raw Material ◽  
Vacuum System ◽  
X Ray ◽  
Pump Pressure

Graphene has attracted significant interest because of its excellent electrical properties. However, a practical method for producing graphene on a large scale is yet to be developed. Graphene oxide (GO) can be partially reduced to graphene-like sheets by removing the oxygen-containing groups and recovering the conjugated structure. GO can be produced using inexpensive graphite as the raw material via cost-effective chemical methods. High vacuum and temperature (10−7 mbar and 1100°C, respectively) conditions are well-known to enable the preparation of reduced powder at the laboratory scale. However, a large-scale high vacuum reduction system that can be routinely operated at 10−7 mbar requires considerable initial capital as well as substantial operational and maintenance costs. The current study aims at developing an inexpensive method for the large-scale reduction of graphene oxide. A stainless steel vessel was evacuated to backing-pump pressure (10−2 mbar) and used to process GO at a range of temperatures. The reduction of GO powder at low vacuum pressures was attempted and investigated by X-ray diffraction and Fourier transform infrared spectroscopy. The experimental results of processing GO powder at various temperatures (200–1000°C) at relatively low pressures are reported. The microstructures of the processed materials were investigated using scanning electron microscopy and chemical microanalyses via energy dispersive X-ray analysis.

Microwave Sintering and Melting of Titanium Powder for Low-Cost Processing

2010 ◽  
Vol 436 ◽  
pp. 131-140 ◽  
Author(s):  
Ralph W. Bruce ◽  
Arne W. Fliflet ◽  
Hugo E. Huey ◽  
Chad Stephenson ◽  
M. Ashraf Imam
Keyword(s):  
Titanium Powder ◽  
Low Cost ◽  
Microwave Sintering ◽  
High Vacuum ◽  
Cost Effective ◽  
Naval Research ◽  
Energy Usage ◽  
Electrode Consumption ◽  
Microwave System ◽  
Direct Induction

The emerging reduction technologies for titanium from ore produce powder instead of sponge. Conventional methods for sintering and melting of titanium powder are costly, as they are energy intensive and require high vacuum, 10-6 Torr or better, since titanium acts as a getter for oxygen at high temperature, adversely affecting mechanical properties. Other melting processes such as plasma arcs have the additional problem of electrode consumption, and direct induction heating of the titanium powder is problematic. Microwave sintering or melting in an atmospheric pressure argon gas environment is potentially cost effective and energy efficient due to the possibility of direct microwave heating of the titanium powder augmented by hybrid heating in a ceramic casket. We are investigating this approach at the Naval Research Laboratory using an S–Band microwave system. The experimental setup and the results of melting and sintering experiments will be described including a rough estimate of energy usage.

Low-Cost, Atmospheric-Pressure Scanning Transmission Electron Microscopy

2011 ◽  
Vol 19 (3) ◽  
pp. 16-20
Author(s):  
Niels de Jonge ◽  
Elisabeth A. Ring ◽  
Wilbur C. Bigelow ◽  
Gabriel M. Veith
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Atmospheric Pressure ◽  
Low Cost ◽  
High Vacuum ◽  
Nanoscale Systems ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Thin Electron

Solid materials in subambient gaseous environments have been imaged using in situ transmission electron microscopy (TEM), for example to study dynamic effects: carbon nanotube growth, nanoparticle changes during redox reactions, and phase transitions in nanoscale systems. In these studies the vacuum level in the specimen region of the electron microscope was increased to pressures of up to 10 mbar using pump-limiting apertures that separated the specimen region from the rest of the high-vacuum electron column, but it has not been possible to achieve the higher pressures that are desirable for catalysis research. TEM imaging at atmospheric pressure and at elevated temperature was achieved with 0.2-nm resolution by enclosing a gaseous environment several micrometers thick between ultra-thin, electron transparent silicon nitride windows. Although Ångström-level resolution in situ TEM has been demonstrated with aberration-corrected systems, the key difficulty with TEM imaging is its dependence on phase contrast, which requires ultra-thin specimens, limiting the choice of experiments.

Hermetically Sealed Glass Packages

2015 ◽  
Vol 2015 (1) ◽  
pp. 000375-000378 ◽  
Author(s):  
Roupen Keusseyan ◽  
Tim Mobley
Keyword(s):  
Thin Film ◽  
Flip Chip ◽  
Low Cost ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Glass Wafer ◽  
Cost System ◽  
Expansion Matching ◽  
Technical Material ◽  
New Generation

Significant advances have been accomplished in the field of Through Glass Via (TGV) technology; enabling a new generation of electronic designs that achieve higher performance, while leveraging low cost system solutions. Through-hole creation methods in glass have been optimized for mass production with consistent via diameter, shape and wall chemistry/morphology. This has enabled the development of unique copper via metallization materials that exhibit very high conductivity, thermal expansion matching (with borosilicate glass) and hermeticity in the 10E-10 Atm.cc/sec range (Ultra-High Vacuum Hermeticity). Further developments in Chemical Mechanical Polishing (CMP) for glass wafers with copper vias, surface sensitization and metal deposition techniques, have enabled thin film metallization on both sides of the glass wafer for fine line redistribution layers (RDL). The thin film RDL is compatible with the TGV with excellent continuity in conductivity. The RDL metallization is plated to allow flip chip, land grid array, wire-bond, solder, or other interconnection methods. The paper will discuss the technical, material and process challenges in each of the areas mentioned above which enable a hermetically sealed glass package. Detailed data and experimental results will be discussed.

Low Cost Thermal Vacuum Testing Facility for Electronic Units

1988 ◽  
Vol 31 (6) ◽  
pp. 30-38
Author(s):  
Elhanan Dgany ◽  
Eytan Kochavi ◽  
Shimon Gruntman ◽  
Asher Kinan
Keyword(s):  
Low Cost ◽  
High Vacuum ◽  
Cost Effective ◽  
Acceptance Testing ◽  
Thermal Vacuum ◽  
Pumping System ◽  
Heating And Cooling ◽  
Performance Requirements ◽  
Testing Facility ◽  
Vacuum Testing

A thermal vacuum testing facility for electronic units has been specified, designed, and built. It is fully operational and performs its tasks—thermal vacuum qualification and acceptance testing of electronic units. All performance requirements and design details have been carefully evaluated on a cost-effective basis, resulting in achieving the design goal of low price (purchase, operation, and maintenance) together with ease of operation, maintenance simplicity, and upgrading options. The major cost saving originated from a detailed analysis of thermal vacuum requirements that resulted in low cost substitutes to the common thermal shroud, together with a thermal plate. The plate is actively thermally controlled by a circulating fluid that is temperature regulated by a commercial heating and cooling unit. The high vacuum pumping system includes a diffusion pump with backstreaming holders.

Uses of Physical Vapor Deposition Processes in Photoelectrochemical Water Splitting Systems

2016 ◽  
Vol 3 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Pedro Migowski ◽  
Adriano F. Feil
Keyword(s):  
Water Splitting ◽  
Vapor Deposition ◽  
Physical Vapor Deposition ◽  
Low Cost ◽  
High Vacuum ◽  
Thin Layers ◽  
Photoelectrochemical Cells ◽  
Gas Source ◽  
Deposition Processes ◽  
Semiconducting Electrode

AbstractMost of the hydrogen on planet earth is found bound to oxygen atoms in water, making H2O one of the most promising H2 storage molecules. Large availability, non-toxicity and low cost are among the advantages of using H2O as a H2 gas source. However, the decomposition of water into H2 and O2, called water splitting, needs a large amount of energy, increasing the final cost per kg of hydrogen produced. In this context, the energy provided by the sun may be used to power photoelectrochemical cells (PEC) for water splitting to produce cheap and high purity H2. This mini-review will show recent advances on the use of physical vapor deposition (PVD) methods to improve semiconducting electrode performance. PVD enables the preparation of thin layers of expensive materials over photoelectrodes, therefore decreasing PEC systems manufacture costs. Moreover, the interface of between the semiconductor and the evaporated materials can be optimized under high vacuum conditions used in PVD processes and more efficient PEC systems can be obtained.

Packaging MEM Sensor Arrays

1999 ◽  
Vol 605 ◽  
Author(s):  
T. F. Marinis ◽  
D. A. Fulginiti ◽  
H. G. Clausen
Keyword(s):  
Chemical Sensors ◽  
Sensor Array ◽  
Dynamic Range ◽  
Low Cost ◽  
High Vacuum ◽  
Sensor Arrays ◽  
Ceramic Materials ◽  
Leakage Rate ◽  
Single Chip ◽  
Sensor Package

AbstractMany applications of MEM sensors require hermetic or high vacuum packaging of sensor clusters. For example, multiple gyroscopes or accelerometers are fabricated on a single chip to improve alignment and stability of input axes or increase the dynamic range of instruments. Chemical sensors are fabricated as large arrays to both improve selectivity and increase the number of species that can be detected. Still larger arrays of sensors must be packaged for hydrophone and bolometer imaging devices. All of these applications place a demanding combination of requirements on the sensor package. The electrical outputs of the sensor array must be well isolated from each other as well as power and excitation signals, while parasitic capacitance is minimized. The package must also be capable of being evacuated and sealed to achieve a pressure of 5 millitorr with a leakage rate below 10−11 [Std cc sec−l]. Finally, the package must be compact and low cost to realize these same attributes of the MEM sensor. This paper describes a packaging approach that is based on low temperature cofired ceramic materials. This technology meets the packaging requirements of sensor arrays and is well suited to the research environment in which the sensor design is continually evolving.

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