Wavelength encoded fiber sensor for extreme temperature range

2010 ◽  
Author(s):  
D. Barrera ◽  
V. Finazzi ◽  
G. Coviello ◽  
A. Bueno ◽  
S. Sales ◽  
...  
Keyword(s):  
Extreme Temperature ◽  
Fiber Sensor ◽  
Temperature Range

Reliability of Ceramic Column Grid Array (CCGA717) Interconnect Packages Under Extreme Temperatures for Space Applications*

2010 ◽  
Vol 7 (1) ◽  
pp. 16-24 ◽  
Author(s):  
Rajeshuni Ramesham
Keyword(s):  
Thermal Cycling ◽  
Experimental Test ◽  
High Reliability ◽  
Extreme Temperature ◽  
Electrical Performance ◽  
Extreme Temperatures ◽  
Thermal Cycles ◽  
Space Applications ◽  
Temperature Range

Ceramic column grid array packages have been increasing in use based on their advantages such as high interconnect density, very good thermal and electrical performance, compatibility with standard surface-mount packaging assembly processes, and so on. CCGA packages are used in space applications such as in logic and microprocessor functions, telecommunications, flight avionics, and payload electronics. As these packages tend to have less solder joint strain relief than leaded packages, the reliability of CCGA packages is very important for short-term and long-term space missions. CCGA interconnect electronic package printed wiring boards (PWBs) of polyimide have been assembled, inspected nondestructively, and subsequently subjected to extreme temperature thermal cycling to assess the reliability for future deep space, short- and long-term, extreme temperature missions. In this investigation, the employed temperature range covers from −185°C to +125°C extreme thermal environments. The test hardware consists of two CCGA717 packages with each package divided into four daisy-chained sections, for a total of eight daisy chains to be monitored. The CCGA717 package is 33 mm × 33 mm with a 27 × 27 array of 80%/20% Pb/Sn columns on a 1.27 mm pitch. The resistance of daisy-chained, CCGA interconnects was continuously monitored as a function of thermal cycling. Electrical resistance measurements as a function of thermal cycling are reported and the tests to date have shown significant change in daisy chain resistance as a function of thermal cycling. The change in interconnect resistance becomes more noticeable as the number of thermal cycles increases. This paper will describe the experimental test results of CCGA testing under extreme temperatures. Standard Weibull analysis tools were used to extract the Weibull parameters to understand the CCGA failures. Optical inspection results clearly indicate that the solder joints of columns with the board and the ceramic package have failed as a function of thermal cycling. The first failure was observed at the 137th thermal cycle and 63.2% failures of daisy chains have occurred by about 664 thermal cycles. The shape parameter extracted from the Weibull plot was about 1.47, which indicates the failures were related to failures that occurred during the flat region or useful life region of the standard bathtub curve. Based on this experimental test data, one can use the CCGAs for the temperature range studied for ∼100 thermal cycles (ΔT = 310°C, 5°C/minute, and 15 min dwell) with a high degree of confidence for high reliability space and other applications.

scholarly journals SiGe BiCMOS Precision Voltage References for Extreme Temperature Range Electronics

2006 ◽  
Author(s):  
Laleh Najafizadeh ◽  
Chendong Zhu ◽  
Ramkumar Krithivasan ◽  
John D. Cressler ◽  
Yan Cui ◽  
...  
Keyword(s):  
Extreme Temperature ◽  
Temperature Range ◽  
Sige Bicmos ◽  
Precision Voltage

Major Breakthrough in Load Capacity, Speed and Operating Temperature of Foil Thrust Bearings

2005 ◽  
Author(s):  
Hooshang Heshmat
Keyword(s):  
Gas Turbines ◽  
High Speed ◽  
Operating Temperature ◽  
Load Capacity ◽  
Extreme Temperature ◽  
Free System ◽  
Thrust Bearings ◽  
Temperature Range ◽  
Foil Bearings ◽  
Temperature Capability

This paper describes major breakthroughs in foil thrust bearings achieving a thrust load capacity in excess of 570 kPa (83 psi), supersonic tip speed of 625 m/s (2050 ft/s) and temperature capability of 815 °C (1500 °F). Compliant foil bearings surpass many of the inherently show-stopping and debilitating features of rolling element bearings. Foil Bearings not only provide an environmentally-friendly, oil-free system of support, but are also well suited for high speed and extreme temperature applications such as gas turbines, compressors, turbochargers, cryogenic-turbopumps, turboexpanders, high speed motors and others. Modern foil bearings have demonstrated stable operational capabilities at super-critical speeds due to their tribodamping intrinsicality and ability to operate with any process fluid (gas or liquid). Recent developments have allowed increased operating temperatures, soaring to 815 °C and above, thus, providing a broader operational temperature range from deep cryogenic to extreme high temperatures. Foil journal bearings received more research and development attention in the past, achieving load capacity of 670 kPa (97 psi), reported by Heshmat in 1994. Foil thrust bearings’ load capacity at that time was in the range of 150 kPa to 200 kPa (20–30 psi) and their temperature capability was ambient to 150 °C (300 °F). This paper discusses a recent major breakthrough in the improvement of the load capacity, high speed capability of compliant foil thrust bearings, as well as extending their operating temperature range to 815 °C. Applying the available analytical tools and newly developed coatings, new thrust bearings have been designed with improved bearing geometry and structural compliancy. The advancement in solid lubricant coatings provided excellent tolerance to intermittent high-speed rubs, thus, making the bearings more robust against shock and extreme loadings. These advanced bearings, with outer diameters ranging from 90 mm to 230 mm, demonstrated a load capacity of 570 kPa (82.7 psi) at 200 m/s runner tip speed. This achievement constitutes two-fold improvement over any state-of-the-art hydrodynamic foil thrust bearings ever reported in the literatures and significantly expands the envelope of possible bearing applications. Improving the bearing load capacity at speeds near Mach 1.6 and higher is also discussed, as well as hydrodynamic operation of a foil thrust pad at 815 °C.

Characterization of Electrical Failure Modes in Chip-on-Board Assemblies for Extreme Temperature Environments

2005 ◽  
Author(s):  
Donald V. Schatzel ◽  
Andrew A. Shapiro
Keyword(s):  
Failure Modes ◽  
Technology Development ◽  
Extreme Temperature ◽  
Development Program ◽  
Temperature Cycle ◽  
Outer Planet ◽  
Science Laboratory ◽  
Mars Science Laboratory ◽  
Temperature Range ◽  
Different Types

Future space missions to Mars and the outer planets will have to operate on the planet surface in temperatures that range from −200°C to 40°C. These missions will require sensors, instruments and motors to operate for extended periods that exceed the duration of any planetary surface mission to date. Currently the Mars Science Laboratory rovers planned for 2009 will be required to survive a mission life of about 500 Martian sols. The Martian solar day is called a sol and is equal to 24 hours and 39 minutes of an Earth day. This extended mission requirement is beyond the reliability threshold of present electronic materials and interfaces such as those used on the Mars Exploration Rovers. The combination of correct materials, electrical interconnection and packaging design are critical to ensuring long life when the range between minimum and maximum temperatures approach or exceed 200°C. The Jet Propulsion Laboratory as part of the Mars Technology program is performing a series of designed experiments to determine the best electronic packaging materials that would survive 500 Martian sols in the temperature range of −120°C to 85°C. This technology development is part of the preparation effort to design and build survivable electronics for the Mars Science Laboratory rovers and related future outer planet missions. This technology development program is called Temperature Cycle Resistant Electronics (TCRE) and is a 3 year design for electrical interface reliability activity. The experiment team assembled 27 different types of test vehicles which are the result of a full factorial designed experiment. There were 10 samples of each type assembled for statistical confidence to yield a total of 270 test vehicles. The basic test vehicle design consists of silicon die mounted to a substrate with gold wire bond electrical interconnects. Continuous electrical paths were designed into the substrate and the dice. The basic experiment consists of assembling three different types of substrates, three different types of die attach materials and three different types of over coat material. The test vehicles were subjected to 1500 thermal cycles (three times required mission life) from −120°C to 85°C over nine months. Open electrical circuits were observed over time due to material interactions over this temperature range that created electrical failures. This paper summarizes the failure results and identifies the material sets that survived this phase of the experiment for 1500 extreme temperature cycles.

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