MSA Optical Unit

The MSA Optical Unit is offered in six configurations that allow individual or combined in-plane measurements, out-of-plane measurements or topography measurements. Depending on system type, the optical unit comprises the MSA-500 head with microscope optics as well as a single-point (Polytec OFV-551) or differential (Polytec OFV-552) fiber optic interferometer. In all configurations, the MSA-500 Sensor Head has optimized microscope optics, an integrated LED illumination unit and a progressive scan video camera which provides a live video stream for the Data Management System. 

MSA Processing Unit

The MSA-500 Processing Unit comprises the Data Management System with MSA Software, the MSA-E-500 Junction Box and, in system configurations that include vibrometry, the OFV-5000 Vibrometer Controller.

MSA Software

The MSA Software comprises the different programs for data acquisition and evaluation:

• Polytec Scanning Vibrometer (PSV) software for out-of-plane measurements offers quick and easy set up, simple data acquisition and outstanding 3-D data visualization.
• Planar Motion Analysis (PMA) software similarly controls the in-plane measurement process and provides a dynamic visualization.
• Topography Measurement System (TMS) Software for data acquisition, analysis, 2-D and 3-D data representation, including profile cuts.

Configurations

The MSA-500 Micro System Analyzer can be configured to cover many operating modes and measurement ranges needed to characterize microstructures. The following table helps to match the appropriate system to the application. Polytec provides systems for either single-task or combined measurements. For out-of-plane vibration measurements, the system can be configured for either single-beam or differential operation. Differential systems can perform both single-beam and differential measurements. In addition to the standard 1.5 MHz version, there is a 24 MHz option that features both high-frequency data acquisition and a high-frequency waveform generator.

Incorporated in the MEMS design and test cycle, the MSA-500 provides precise 3-D dynamic and static response data that simplifies troubleshooting, enhances and shortens design cycles, improves yield and performance, and reduces product cost. This outstanding degree of innovation has been recognized by two prestigious awards: the 2005 Sensor Innovation Award and the Photonics Circle of Excellence for the development of microscope-based scanning vibrometry.

The combination of two complementary measurement techniques for investigating the vibrational behavior of small structures provides superior performance. For example, it can quickly identify, visualize and measure system resonances and transient responses, enhancing overall measurement productivity. This improved efficiency is especially important when integrating the measurement system into automated processes for MEMS production environments. Single-technology solutions like ESPI, white light interferometry, and phase-shifting interferometry give a much more limited view of small structure response.

Using wide-band excitation, the highly sensitive laser-Doppler technique can rapidly find all mechanical resonances (in-plane and out-of-plane) without prior information. In a second step, stroboscopic video microscopy is used to obtain accurate amplitude and phase information of in-plane resonances identified through laser vibrometry.

• Rapid identification and visualization of both system resonances and static topography
• Integrated microscope optics with optimized optical path for best lateral resolution and highest image quality
• Easy integration with MEMS/wafer probe stations
• Simple and intuitive operation, ready to measure within minutes
• Increased productivity through short measurement cycle
• Accelerates product development, troubleshooting and time-to-market

• Full-field vibration mapping and broadband, out-of-plane frequency response information
• Displays frequency-domain and time-domain data, simplifying transient response analysis
• High-density sample grids with up to 512 x 512 user-defined measurement points
• Versatile data import and export interfaces to validate FE models
• Submicron laser spot for measuring very small structures and details
• Laser dimmer for optimized measurement conditions

• Stroboscopic video measurement of in-plane motion with frequencies up to 1 MHz
• Time-domain displacement measurements with nanometer resolution
• Integrated signal generator for step-response, ring-down and Bode plot measurements
• Time-saving, automatic multiband processing

• Rapid, non-contact 3-D topography measurement with subnanometer resolution
• Determination of structure heights and shape on both rough and specular surfaces
• Overlay technique copes with different contrast levels and material mixes
• Powerful TMS software for topography and surface characterization
• 2-D and 3-D presentation with video overlay

The sensor head can be mounted to a stand provided by Polytec or to a commercially available probe station. Polytec stands are available with vibration- isolated workstations or can be installed on user supplied optical tables. The MSA Processing Unit can be mounted in the convenient 19’’ System Cabinet that houses the Vibrometer Controller, Data Management System, Junction Box and cabling, or likewise in the System Cabinet Extension. Both versions keep the electronic components separated from the work surface to reduce the influence of ambient noise on the test object. Different types of focus blocks are provided for z adjustment of the measurement head relative to the measurement object.

For more information about accessories, please contact your local Polytec sales/application engineer.

By combining Polytec’s Micro System Analyzer with a MEMS/wafer probe station the user can concentrate on the dynamic test rather than on sample holding, positioning and contact issues. Commercially available probe stations offer control of the test environment and a stable platform to mount the MEMS tools. Thus, a MSA-500 integrated with a quality general-purpose probe station equipped with a thermal chuck system can provide a one-stop workstation to test, repair and encapsulate MEMS devices.

The mounting holes of the MSA-400 are equivalent to a Mitutoyo FS70-L-S (short base) back plate. Thus it can be attached to most of the commercially available probe stations that have the same array of mounting holes. Please ask your Polytec sales/application engineer for details.