Packaging constitutes one of the most costly steps of MEMS/MOEMS manufacturing. The package protects the MEMS devices and, in the case of MOEMS, it also provides light access to the device. In many cases, MEMS require a specific atmosphere for their proper functioning. The atmosphere should be kept invariable during the lifetime of the package in order to not degrade the performance of the device. Maintaining a constant atmosphere inside the package becomes more challenging as the cavity volume is decreased to the microliter and nanoliter range. Other packaging requirements are compatibility with wafer-level microfabrication techniques (cost reduction) and low temperature assembly in cases where temperature sensitive devices are to be packaged. In recent years, INO has performed a great amount of work towards the development of uncooled IR microbolometer detectors using VOx technology. Different pixel designs have been optimized for different applications. The bolometer pixels require a vacuum atmosphere below 10 mTorr to be maintained during the lifetime of the device in order to operate at their highest sensitivity. INO's micropackaging technology has been demonstrated to provide base pressures below 5 mTorr. An equivalent flow rate of 2.5×10^-14 Torr.l/sec has been obtained for a device packaged without any getter. The advantages of INO's micropackaging technology are the possibility of achieving very low base pressures, the low temperatures required for the assembly (the package device is never exposed to a temperature above 150 °C) and its compatibility with hybrid wafer-level packaging. The technology has been developed for the micropackaging of INO's 160×120 pixel uncooled microbolometer FPA, but it is compatible with any other kinds of MOEMS-MEMS devices requiring vacuum hermetic packaging. In order to increase the lifetime of the package, knowledge of the gases outgassing inside the package is crucial. A hybrid approach has been chosen as it permits packaging only known-good dies and saving considerable quantities of IR window material. In INO's hybrid wafer-level packaging, dicing is performed only through one of the wafers, therefore reducing the risk of perturbing the vacuum during the separation of the different dies.

We present a sophisticated method for the packaging of a micro-electro-mechanical biochip, which leaves the sensitive surface area of the chip uncovered to allow for direct contact to aqueous environment. Together with adequate integration in a fluidic cartridge, the packaging method allows for the realization of a lab-on-chip (LOC). A fluidic interface to the cartridge is provided as well as electrical interfaces to the biochip electronics located in a readout instrument. The biochip features a central membrane and electrodes, both located in the central chip area, and bond pads distributed along the rim of the chip. The packaging method ensures a hermetic separation between the membrane sensing area interfaced to liquids and the bond pad area. Challenging was the fact that both, the freely moving membrane and the bond pads for electrical interconnection are positioned very close to each other on the same chip surface area. We mounted the biochip into a recess of a rigid printed circuit board and electrically connected it to the latter with a proprietary MicroFlex Interconnection (MFI) technology. A customized coating method using a specially shaped silicone casting-mold ensured a very thin, hermetic encapsulation, which left the membrane safe and freely accessible.

INO has extensive experience in the design and fabrication of focal plane arrays (FPAs) of uncooled microbolometers. In particular, the FPA of 512×3 microbolometers, developed in collaboration with the Canadian Space Agency (CSA), has been selected for use in the NIRST (New Infrared Sensor Technology) radiometer of the SAC-D Aquarius mission. The FPA has been designed for pushbroom scanning of the Earth to provide radiometric data in the mid- and long-wave infrared for the monitoring of fires as well as thermal mapping of ocean temperature. Uncooled microbolometer detectors are suited for space applications due to their low power consumption while still exhibiting adequate performance. Furthermore, the spectral range of their response could be tuned from the mid- to the far-infrared to meet different mission requirements. In order to ensure that the detector receives only the thermal contribution from the desired target and to minimize radiometric error due to variation of the temperature of the surrounding during the measurements, a radiometric package is required. In a radiometric package the detector environment is thermally stabilized by means of a temperature controlled radiation shield. The radiation shield should also be designed to prevent stray radiation from reaching the detector. Under the Space Technology Development Program of the CSA, INO has designed, assembled and tested a radiometric package in order to characterize its performance and compatibility with the space environment. The operating spectral band is defined by the spectral characteristics of a bandpass filter placed in front of the FPA. For typical space missions, the package must pass standard environmental tests without degradation of its performance (thermal cycling from -55 to +85 °C according to MIL-STD-810, random acceleration up to 14 G RMS from 20-2000 Hz and shock up to 75 G). In order to ensure reliability in those conditions while maintaining optimum performance, an adequate selection of materials is necessary. In this paper, INO's radiometric packaging technology for uncooled microbolometer FPA's will be presented. The selection of materials will be discussed and the final choices presented based on thermal simulations and experimental data. The effects of different design parameters on the performance, such as material, shape and thickness of radiation shield and choice of adhesive have been studied. An instantaneous noise equivalent temperature difference (NETD) of ~ 20 mK was obtained under the measurement conditions (broadband LWIR, 140 ms integration time, f/1 optics, characterization in flood exposure). The design of the package reduced the contribution of environmental temperature variations on the offset of the sensor. The equivalent response of the package varied less than 0.08 °C per degree of variation of the temperature of the package. The package also showed low sensitivity to stray radiation as a result of the effectiveness of the radiation shield design. The device successfully passed the prescribed environmental tests without degradation of performance.

An analysis method for fine leak batch testing is developed for effective hermeticity inspection of metal-sealed MEMS packages in a mass production environment. It employs a forward-stepwise regression analysis based on a physical gas flow model to infer the information of leaky packages from batch test data. The proposed method can determine accurately the number of leaky packages and the true leak rate of each leaky package when the number of leaky packages in a batch is less than 5. A top-down hierarchical batch test is proposed as a reliable and effective test scheme by addressing this limitation of the developed analysis scheme.

The primary cause of corrosion, stiction or other failure mechanisms within hermetically sealed enclosures has historically been viewed as due to increases in internal moisture concentrations. It has historically been postulated that the primary source of moisture in these enclosures is the failure to achieve hermeticity at seal, or the loss of hermeticity post-seal. This postulation is the basis for failure analysis and mitigation both in the appropriate standards like MILSTD- 883 and in industrial QA procedures. Empirical observation of many data sets over the past 20+ years shows that this postulation does not always hold up in practice. The purpose of the current work is to test this postulation through the analysis of archival microelectronic packages and data sets of various ages. Internal gas composition data for three different sets of packages totaling 165 units is reviewed. Of these, 63 were noncompliant (>0.50v%) on internal moisture, but only 8 (12.7%) showed an internal gas composition "signature" consistent with air leaking into the enclosure. These data suggest that leaks play a minor role in gas composition change within enclosures and that outgassing from materials is the principal contributor to internal moisture concentrations and the failure modes they induce.

A novel inverse approach based on an optical leak test is developed and implemented for in-situ measurement of gas diffusion properties of polymeric seals used in MEMS packages. Cavity pressure evolution during a leak test is documented as a function of time using laser-based interferometry, and the diffusion properties of a polymeric seal are subsequently determined from the measured pressure history. A comprehensive numerical procedure for the inverse analysis is established considering three diffusion regimes that characterize the leak behavior through a polymer seal. The method is demonstrated successfully to determine the helium diffusivity and solubility of the polymeric seal used in a package.

Self-sensing and dispersive evaluation were investigated with different dispersion solvents for single carbon fiber/acid treated carbon nanotube (CNT)-epoxy composites by electro-micromechanical technique and acoustic emission (AE) under cyclic loading/subsequent unloading. Gradient nanocomposite specimen was used to obtain contact resistivity using two- and four-probe method. Optimized dispersion procedure was set up to obtain improved mechanical and electrical properties. The case using good dispersion solvent exhibited higher apparent modulus and lower electrical contact resistivity for both the untreated and acid-treated CNT-epoxy composites. It is because of better stress transferring effect and enhanced interfacial adhesion. Micro-damage sensing was also detected simultaneously by AE combined with electrical resistance measurement. It exhibited the stepwise increase with progressing fiber fracture due to the maintaining numerous electrical contacts of CNT. Thin network of CNT by dipping method was formed on glass substrate to obtain conductive and transparent plate by UV transmittance.

As tribological properties are critical factors in the reliability of microelectromechanical systems, it is important to understand the physical processes and parameters governing wear and friction in silicon structural films. Dynamic friction, wear volumes and wear morphology have been studied for polysilicon devices from the Sandia SUMMiT V^TM process actuated in ambient air at μN loads. A total of seven devices were tested. Roughly half of the devices showed a peak in the friction coefficient at three times the initial value with failure after 105 cycles. The other half of the devices behaved similarly initially; however, following the friction coefficient peak they displayed a lower steady-state friction regime with no failure for millions of cycles. Additionally, the nanoscale wear coefficient and roughness increased in the first ~10⁵ cycles and then slowly decayed over several million cycles. Transmission electron microscopy studies revealed amorphous oxygen-rich debris. These measurements show that after a short adhesive wear regime, abrasive wear is the governing mechanism with failures attributed to differences in the local nanoscale surface morphology. Changing the relative humidity, sliding speed and load was found to influence the friction coefficient, but re-oxidation of worn polysilicon surfaces was only found to have an effect after periods of inactivity.

This paper presents a testing methodology for measuring the low cycle fatigue properties of single-crystal silicon thin films using kHz-frequency resonators. The dynamic behavior of the fatigue structures is thoroughly characterized to allow accurate measurements of stresses (±0.1 GPa) and fatigue lives (±250 cycles). The tests consist of applying successive bursts of small numbers of cycles (as low as ~500 cycles) and measuring the resonant frequency in between each burst. Continuous damage accumulation, beginning after the first burst, is observed based on the decrease in resonant frequency of the resonant structure.

Micro-electromechanical sensors have been developed for high-frequency voltage metrology applications. They should ultimately allow RF to DC voltage transfer. The conventional measurement principle is based on RF power dissipation by ohmic resistances allowing RMS voltage conversion by the square power law. The principle of electrostatic force, which has already been demonstrated to work from DC to gigahertz frequencies, is a completely novel principle for RMS voltage measurement. An elastically suspended plate is subjected to the electrostatic pressure of a voltage and the resulting deflection is measured using a capacitive feedback circuit. For calculability and reproducibility purposes, the geometry of the devices has to be known as exactly as possible. The sensitivity is maximized by a construction with relatively large plates divided by a small gap only and a suspension with a very low spring constant. A key factor for the use in metrology applications is the stability and reliability of the devices. Therefore, bulk-silicon is taken for the suspension of the movable plate. It is a readily available micro fabrication material with high grades of purity. Moreover, it has virtually no region of plastic deformation and is fatigue free. Devices have been manufactured using bulk-silicon with a thickness of 350 μm down to 20 μm for the suspension. In this contribution, we examine the stability and reliability of these sensors as well as the influence of other environmental factors on the performance of the devices.

Reliability testing of MEMS resonators has grown significantly in importance since these devices moved into high volume production. In line with this development, we present an automated phonon detection-based test setup, which utilizes a piezoelectric transducer to translate resonator mechanical motion into voltage, for investigating the long-term frequency stability of clamped-clamped beam resonators. The automated test system we have developed is able to continuously actuate up to four devices and characterize them every 30 minutes to monitor resonance frequency f₀ and Q-factor changes resultant from long-term actuation. The surface temperature of the devices is also carefully monitored and the temperature data is used to compensate for the f₀ variations caused by temperature fluctuations. The compensated f₀ measurements obtained over time can be used to determine the frequency drift of the resonators. Q-factor degradation and variations in resonator in-plane displacement can also be detected by our system. The test system was used to monitor the behaviour of a 168.502 kHz resonator over a 225-hour operating period. The device was actuated in its linear mode at 29 ±1.0 °C and ~10^-1 Pa. It showed an f₀ shift of -1.092 Hz/day with Q-factor remaining at ~27,000 throughout. Resonator displacement was also consistent over the actuation period.

This work deals with in-line measurement techniques for quantification of important microsystems parameters and related scattering caused by the process conditions. Material properties, mechanical stress but also geometrical dimensions and their tolerances are characterized by indirect method, based on specially designed test-structures. This method involves a data fusion process that combines numerically calculated and experimentally determined information to estimate sought parameters. Laser Doppler Vibrometrie is used to determine the frequency response function (FRF) of the test-structure and find out their Eigenfrequencies. For the numerical simulation of the test-structures a parametrical finite element (FE) model is used and a series of pre-stressed modal analyses have been performed. Hence the dependence of the Eigenfrequencies on parameters of interest is obtained. The comparison to the measured frequencies yields the values of the desired parameters. The test-structures are designed, produced and used for microsystems manufacturing monitoring in Bonding and Deep Reactive Ion Etching (BDRIE) processes. An optimization of the teststructures' form for a nontrivial goal function is shown. Measurement results of the presented technique are comparable with results of common characterization methods. The presented technique is both in-situ and non-destructive.

The new, simple low-voltage cathodoluminescece set-up was designed and plotted. The set-up was designed on the base of field emission light emitting device with carbon nanotube (CNT) cold cathode and anode covered by layer of nancrystalline phosphor. The concept of set-up allowed for measuring of emissive properties of even 8 different samples in a very short time. The samples are placed in the vacuum chamber and the luminescent spectra are recorded using outside placed fiber spectrophotometer. The pressure in the set-up is controlled by vacuum sensor. The opportunities and application of presented conception of set-up will be discussed.

The scanning laser display technology is one of the most promising technologies for highly integrated projection display applications (e. g. in PDAs, mobile phones or head mounted displays) due to its advantages regarding image quality, miniaturization level and low cost potential. As a couple of research teams found during their investigations on laser scanning projections systems, the image quality of such systems is - beside from laser source and video signal processing - crucially determined by the scan engine, including MEMS scanner, driving electronics, scanning regime and synchronization. Even though a number of technical parameters can be measured with high accuracy, the test procedure is challenging because the influence of these parameters on image quality is often insufficiently understood. Thus, in many cases it is not clear how to define limiting values for characteristic parameters. In this paper the relationship between parameters characterizing the scan engine and their influence on image quality will be discussed. Those include scanner topography, geometry of the path of light as well as trajectory parameters. Understanding this enables a new methodology for testing and characterization of the scan engine, based on evaluation of one or a series of projected test images. Due to the fact that the evaluation process can be easily automated by digital image processing this methodology has the potential to become integrated into the production process of laser displays.

Research and development of microelectromechanical systems (MEMS) has shown a significant promise for a variety of commercial applications. For example, accelerometers are widely used for air bags in automobiles, MEMS inkjet print heads are used for printers, gyroscopes for guidance and navigation and pressure sensors for various industrial applications. Some of the MEMS devices have potential to become the commercial-off-the-shelf (COTS) components. Aerospace requires more sophisticated technology development to achieve significant cost savings if they could utilize COTS components in their systems. A miniature gas chromatograph instrument designed as a space station project will provide onorbit detection, identification, and quantification of potentially toxic trace volatile organic compounds in the human-supporting environment. The instrument consists of several commercial off-the-shelf (COTS) valves, pumps and sensors. This paper describes the thermal environmental requirements and protoflight/qualification thermal test results for the COTS parts at cold and hot temperature extremes. The objective of this study is to qualify several COTS components for specific thermal/dynamic environments to assess their reliability. All COTS components life tested were believed to meet the 3x mission operational life requirements. Test results will be presented.

This paper presents a configuration of a novel surface acoustic wave (SAW) micro-electro-mechanical-systems (MEMS) interdigital transducer (IDT) gyroscope different from the current SAW MEMS-IDT gyroscope consists of a two-port SAW resonator and a delay line as the sensor, this paper provides a new configuration of SAW gyroscope based on the interference effect of two crossed SAWs, one is induced by the Coriolis force from the input rotation, and the other is from the SAW device with same operation frequency. A differential structure of two delay line oscillator is used to compensate the temperature effect. Based on the coupling of modes (COM) simulation, an 80MHz two ports SAW resonator and dual-delay line were fabricated and characterized by the HP network analyzer. In the primary gyroscope experimental results, a frequency change of 2500Hz was observed at rate of 500 deg/s from the SAW delay line by interference effect between the secondary SAW induced by Coriolis force and the running SAW from the delay line.