The Lumenarium: The official blog of Lumetrics, Inc.

Materials Cross-Section Using a Low-Coherence Interferometer

Posted July 18, 2017 by Kristin
Abstract — Optical thickness metrology techniques rely on illuminating the sample of interest with light and analyzing the reflections. These techniques work best on objects with smooth surfaces: glass lenses, windows, plastic webs, etc. However, measurement capabilities of such instruments deteriorate in situations where the reflected light is affected by imperfect surfaces, due to optical scattering or absorption. This application note describes a method of obtaining thickness information for such imperfect samples using its optical cross-sectional view acquired in a non-destructive way. The method employs the commercially available instrument, OptiGauge II, which is based on time-domain low-coherence interferometry.

filed under: Non contact thickness measurement, optical thickness measurement, optical metrology

Real-time Group Refractive Index Measurement Of Fluids Using Interferometry

Posted June 21, 2017 by Kristin

Abstract — Maintaining proper chemical composition of fluids is an important control parameter for a variety of different production processes. This is especially critical in the medical device manufacturing to maintain high quality standards. One method to monitor fluid composition is to measure its refractive index.

filed under: Non contact thickness measurement, optical thickness measurement, refractive index measurement, interferometry, metrology, liquid refractive index measurement

Automated Dimensional Measurement of Microfluidic Flow Cells

Posted May 31, 2017 by Kristin

Abstract—Lumetrics, Inc. (Rochester, NY) has made inspection of internal dimensions of microfluidic flow cells possible with low-coherence white light interferometry. The OptiGauge II can measure internal channel heights down to 12 microns with 100 nanometer precision quickly and non-destructively. Machine vision-aided inspection stations can quantify other critical dimensions of entire production runs, ensuring higher product quality and that the performance specifications are met.

filed under: Non contact thickness measurement, optical thickness measurement, flow cell, machine vision, interferometry, metrology, microfluidics

Optical Thickness and Flatness Measurement of Bonded Silicon Wafer Assemblies

Posted January 18, 2017 by Kristin

AbstractThe silicon wafer manufacturing process relies heavily on precision polished wafers that have uniform thickness and, depending on the application, also control parallelism to a secondary wafer after bonding.
Lumetrics’ low coherence interferometer, commercially marketed as OptiGauge II, is a device capable of measuring the simultaneous wafer thickness, adhesive thickness, and parallelism between surfaces to sub-micron precision. Combined with custom software and a precision XY raster scanner, a wafer or wafer assembly can be fully characterized with respect to layer thicknesses and surface parallelism.
Index Terms—adhesive, flatness, interferometry, metrology, optical thickness measurement, parallelism, silicon, wafer

filed under: Dimensional Measurement, Lumetrics, Non contact thickness measurement, optical thickness measurement, OptiGauge, OptiGauge II, Thickness Measurement

Upcoming Event: Photonics West 2016

Posted January 18, 2016 by Kristin

Lumetrics will be exhibiting at Photonics West this February in Booth #3018!  Please stop by and say hello- we have lots of new measurement solutions for your manufacturing process.

filed under: Non contact thickness measurement, optical thickness measurement, Optics, OptiGauge, photonics west 2016, SPIE, Thickness Measurement