Laser Spectroscopy
Laser Spectroscopy Customer Case An academic researcher is studying the attenuation properties of different materials inside Laser cavities for applications in Laser Spectroscopy. The Laser pulses are generated by one Laser, and are then transmitted by mirrors into another cavity filled with gaseous material. In the second cavity, the light pulses are continuously reflected by opposite mirrors and their intensities are measured by a transducer which converts them into decaying pulses of 30 nanosecond width. The decay takes about 40 microseconds to settle. The researcher is required to capture the decaying pulses and save the captured data onto the [...]
Using Capacitance Sensors for Non-Conductive Material Measurement GalleryUsing Capacitance Sensors for Non-Conductive Material Measurement
Application Notes-MTI, Brand-MTI, Industry-Compliance Testing, Industry-Consumer Products, Industry-Electronics, Industry-Manufacturing, Industry-Sensors, News-MTI, News-MTI-Instrumentation, Products-MTI-Capacitance, Z-REPUB, z1
Using Capacitance Sensors for Non-Conductive Material Measurement
Non-Conductive Material Measurement with Capacitance Sensors Capacitance sensors are non-contact devices that can be used to obtain position, thickness, and dynamic measurements with a high degree of precision, accuracy, and resolution. Capacitive measurement is used with electrically-conductive materials such as metals but can also be used to measure non-conductive materials such as glass, sapphire, and many plastics. Even if a non-conductive material is relatively inexpensive (such as closed cell foam), manufacturers want to avoid errors that can result in significant waste across high volumes. Importantly, capacitance measurement is also used with semi-insulating materials such as gallium arsenide (GaAs) and [...]
Laser Transient Absorption Spectroscopy
Laser Transient Absorption Spectroscopy Customer Case The customer's setup is a scientific application in which transient signals from a Laser Absorption Spectroscope are transferred to a computer. The laser power is modified in steps and the process is repeated. The measurement sensitivity is limited by noise generated by the current digitizer. The customer wants to capture and continuously average very small pulse responses. The lowest signal pulse height is 0.5 milliVolts and can range up to 2 mV. The duration of each response pulse is 1 to 10 microseconds. The Pulse Repetition Frequency (PRF) is 10 Hz. The customer's [...]
Charge-Couple Device (CCD) Data Capture
Charge-Couple Device (CCD) Data Capture Customer Case The client is involved in developing a charge-couple device (CCD) based system to function as an imaging spectrometer. The spectrometer will image 5x5 mm squares that will form a 50 mm line or 1.5x1.5 mm squares in a 15 mm line. The line is to be imaged on a CCD chip. In this application the customer needs to simultaneously acquire 10 independent spectra that are 200 pixels long each with 12-bit resolution. The read-out rate is 1000 frames per second for a period of 10 seconds. The 12-bit data is to be [...]
Semiconductor Wafer Lapping and Displacement Measurement
Semiconductor Wafer Lapping and Displacement Measurement Semiconductor Semiconductor Wafer Manufacturing Displacement Description Semiconductor Wafer Lapping and Displacement Measurement This application note explains how MTI’s Accumeasure technology was used with a lapping machine to measure displacement (wafer material removal) and determine the new semiconductor wafer thickness. Changes in electrical capacitance (displacement) were measured and then directly converted into a 24-bit digital reading to obtain precise digital thickness measurements. During lapping, a wafer of known start thickness is placed on a rotary lapping table. The backside of the wafer faces downward and toward [...]
Wafer Stress Analysis Using the 300iSA
Wafer Stress Analysis Using MTI Instruments Proforma 300iSA Wafer processing involves several stages that can lead to mechanical changes in the wafer structure. These changes, or stresses, may result in deformities, making the wafer either unusable or only marginally usable. To evaluate these stresses and determine the wafer's quality, wafer stress measurement is essential. The Proforma 300iSA wafer characterization tool offers a powerful solution for wafer stress analysis. It allows for the analysis of a wafer both before and after processing. By comparing these two states, the Proforma 300iSA effectively evaluates the wafer's stress levels and mechanical alterations, providing [...]
Laser Measurement & Characterization of Flat Panel Displays
Laser Measurement & Characterization of Flat Panel Displays Customer Case This customer's application involves the characterization of flat panel displays (used in laptop computers, computer game displays, etc.) via laser scanning. The laser is bounced off a number of mirrors and then through lenses, from which it is scattered. The scattered laser light must then be analyzed in order to determine the quality of the flat panel display. This laser measurement system is used not only by flat panel display industries, but also by disk drive manufacturers to analyze platter quality and, in the near future, for characterizing silicon [...]
Laser Signals Striking Silicon-Diode Target
Laser Signals Striking Silicon-Diode Target Customer Case The customer wants to capture the output of some silicon diodes looking at a laser target. The typical signal is anywhere from 20mv to 1V in amplitude and 0 to 15ns in length. There are up to 16 of these diodes that are looking at the same target. Each diode has a different filter so the post-trigger depth and amplitude-scale must be user-adjustable. Their main interest is to sample and digitize the signals for archiving, with later retrieval and plotting. Fancy software is not needed for display as the data is gathered [...]
Optical Scanning of Drive Media
Optical Scanning of Drive Media Customer Case The customer's application is optical scanning for drive testing. The goal is to identify burnt or damaged spots on the disk. The scanning system is generally used in Quality Control, Head-Disk Interaction and Failure Analysis. There is a need for continuous acquisition during the spiral scan. The speed of the disk is 10,000 RPM and the requirement is to capture 65,000 to 80,000 samples each revolution. A single channel is needed for the acquisition at 10 MegaSamples/second or greater. High vertical resolution will aid in measuring the properties and ultimately the degradation [...]
Capacitance Probes vs. Strain Gauges in Piezo Flexure Stages
Capacitance probes with pico-positioning sensors can be embedded in piezo flexure stages. With minor mounting modifications, these non-contact probes provide significantly greater accuracy than strain gauges. Piezo flexure stages are positioning devices with a high degree of resolution. These motion stages contain a piezoelectric actuator that converts an electrical signal into displacement based on the reverse piezoelectric effect, which is the ability of a piezo electric material to elongate when a voltage is applied. When a voltage (e.g., 0-150 VDC) is applied to the actuator, the stage moves in proportion to the applied voltage. Yet, the exact position remains [...]