Method for examination of a sample by means of the heat flow thermography

US9816866B2 · kind B2 · utility

Assignee

• FEI EFA, Inc. · US

Inventors

• Haymo Lang · Igensdorf, DE
• Jochen Mielke · Bielefeld, DE

Key dates

• Filing date: Dec 10, 2012
• Grant date: Nov 14, 2017
• Expiry date: Sep 2, 2034

Classification

• Technology area (CPC G): Physics
• CPC primary: G01J2005/0077
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

The invention provides a method for a non-destructive, non-contacting and image forming examination of a sample by means of the heat flow thermography method where the examination consists of evaluating an existence and/or depth distance values of any heat flow velocity transitions below a surface of the sample, wherein the sample is excited by heat pulses of at least one excitation source, and a thermal flow originating therefrom is captured by at least one infrared sensor in an image sequence of thermal images, and wherein the thermal images obtained from the image sequence are evaluated by means of a signal and image processing and depicting a thermal flow with a resolution in time and in space. The method comprises: exciting the sample at least twice independently from each other by means of the heat pulses from the excitation source where a second excitation and any succeeding excitation is delayed with respect to a preceding excitation by a time delay whereby the start of the captured sequence happens at another defined point of time within the time between two images within an image sequence; detecting the respective total thermal flow processes generated by the at least two…