PMIC understands that convenience and traceability are important to customers. Additional services are made available wherever space and time allow so that PMIC can assist customers with all their needs.
PMIC offers specimen machining and preparation for a majority of customer materials. Partnering in-house machining capabilities with local high-quality machine shops, PMIC can make sure materials are ready for test to specific tolerances. Specimen machining can add to overall lead time and cost.
OREGON STATE UNIVERSITY COLLABORATION
PMIC is over 80 % staffed by OSU alumni and continues to reach out to the College of Engineering for access to the university’s array of laboratory equipment. PMIC follows ISO/IEC 17025 requirements for off-site testing when completing contracts at OSU.
PMIC wants to provide convenience to customers. For testing which cannot be completed in-house, PMIC has several industry partners with a multitude of capabilities. Per ISO/IEC 17025, PMIC always informs customers when testing is subcontracted. Where possible, all subcontracting is performed by another ISO/IEC 17025 accredited laboratory. PMIC may subcontract or consult with field experts for non-standard and experimental testing.
TIME DOMAIN THERMOREFLECTANCE (TDTR)
TDTR testing can be performed over the temperature range of 296 K to 623 K (23 °C to 350 °C). It is a method to determine the thermal conductivity of thin films up to several hundred µm thick. Specimens must have optically smooth surfaces: mirror-like, 15 µm RMS roughness, with flat and uniform thickness. The volumetric heat capacity (VHC) must be specified for each specimen. Dr. Cahill has partnered with PMIC to offer this testing to customers with thin films and performs testing as a subcontractor.
MACHINE VISION SYSTEMS
Vision system optics and electronics have been used to calibrate antenna structures, measure in-situ thickness as compression force and temperature are changed (Figure 1). Visual systems have also been used to record apparent changes during Thermal Shock testing.
Thermal distortion, such as creep, bend, and twist of structures and components can be analyzed as a function of temperature. Dimensional stability measurements use optical levers and interferometry simultaneously to measure angle and length change. Chambers are customized to the customer’s unique parts (Figure 2) as necessary. Currently, PMIC has chambers for structures up to 2.4 m (8’), as well as powered mechanisms and flight component-capable chambers. The normal temperature range for this testing is 88 K to 458 K (-185 °C to 185 °C) with extended temperature ranges ready for development.
Dimensional stability and thermal distortion testing are critical to assuring engineering precision in limited tolerance designs.
Other tools may include gauge block comparators, modified differential Michelson interferometers, differential LVDT dilatometers, Fraunhofer-Fresnel diffraction-based gages, and Fabry-Perot interferometers.
PMIC has extensive experience in the use of PZT driven E/O modulators and optical positioning devices.
Other test techniques include strain gages and autocollimators.
DIGITAL IMAGE CORRELATION
ARAMIS Camera by Trilion
The optical capabilities of the Trilion ARAMIS offer an expansion of PMIC’s abilities to measure and characterize strain and displacement during testing. ARAMIS can provide accurate measurement resolution of coordinates, displacements, velocities, accelerations, surface strain in both standard and experimental testing. The image mapping and custom calculations features allow PMIC to enhance a number of test features. ARAMIS is a feature of PMIC’s mechanical test system for Poisson’s ratio, Young’s modulus, limit curve, shear modulus, and residual stress analysis. An example is available on the Mechanical Testing Services Page. PMIC is ready to use this tool to enhance visual analysis and understanding in other testing.
PMIC routinely carries out thermal cycling of test samples, components, and structures from 4 K to over 900 K (-269 °C to 627 °C). Custom construction and instrumentation permit extension of both temperature range and test sample dimensions. Thermal cycling over the expected operating range of materials with variable temperature holds can provide valuable data for how materials and designs will hold up over their expected lifecycles in their operating environment.
PMIC rapidly cycles specimens between a minimum and maximum temperature and optically monitors the specimen. Multiple pictures are taken each cycle using a high-resolution camera, and the temperature is continuously recorded. The thermal shock system is currently validated for cycles over the range of 78 K to 811 K (-195 °C to 538 °C).
Video 1: Optical observation of specimen cycled between immersion in nitrogen and induction heating during thermal shock procedure. The video cuts between several minutes of cooling and heating.
PMIC offers its unique and versatile thin-film deposition and characterization capabilities for research and technology development to industry, startups, and academic researchers.
Thin-film deposition, treatment, and metrology tasks can be performed either by PMIC staff as a service or by external users. One of the main strengths and advantages of our unique technical setup is the possibility to perform an in-situ combination of efficient surface cleaning, specimen heating, and physical vapor deposition using sputtering or thermal evaporation. Our 6500 sq. ft lab space accommodates a 72 sq. ft class 1000 (ISO 6) cleanroom container housing the PVD thin-film technique.
• ASTM D257 Standard Test Methods for DC Resistance or Conductance of Insulating Materials
• ASTM B193 Standard Test Method for Resistivity of Electrical Conductor Materials
Electrical resistivity is measured using the Tegam Model 1750 Microohmmeter. Configurations appropriate for a wide variety of sample geometries are used, including standard Kelvin 4-point probe connections for bulk bar-shaped samples, a collinear 4-point probe for thin films, wafers, and flat arbitrarily-shaped samples. Measurements have been made in the temperature range from 88 K to 296 K (-185 °C to 23 °C), and a furnace allows measurements up to 773 K (500 °C).
Surface resistance (Rs) can be measured in the range of 2 mΩ ≤ Rs ≤ 20 MΩ.
Volume resistivity (ρv) can be measured in the range of 10-6 Ω·cm ≤ ρv ≤ 109 Ω·cm.
HALL EFFECT TESTING
• ASTM F76 Standard Test Methods for Measuring Resistivity and Hall Coefficient and Determining Hall Mobility in Single-Crystal Semiconductors
Measuring electrical resistivity under an applied magnetic field supplies information about the carrier concentration, Hall mobility, and majority carrier type of a semiconductor. PMIC has performed Hall Effect testing up to 523 K (250 °C) by partnering with the Oregon State University Magnetics Laboratory. Room temperature testing can be performed with Ø 101.6 mm (4.0”) poles and Ø 50.8 mm (2.0”) poles at magnetic field strengths between ±8 Gauss and ±15 Gauss, respectively.
OPTO-ACOUSTIC EMISSION (OAE)
Laser Michelson interferometry has been adopted at PMIC to record real-time amplitudes and phases of photodetector signals caused by microcracking, especially in composite materials when cooling. Amplitude analysis reveals the defect created (interlaminar matrix crack, fiber break, debonding, etc). Acoustic emission events are detected optically when thermal cycled and offer advantages over conventional acoustic emission techniques. Technical papers are available.
PMIC has used PZT based transducers at frequencies from 150 KHz to several MHz to measure elastic moduli of solids and to detect internal flaws.