The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 18, 1997
Filed:
Jan. 25, 1996
Sergei V Govorkov, Nanuet, NY (US);
Inrad, Northvale, NJ (US);
Abstract
A device and method for measuring the thermal conductivity of a thin film by determining the change in temperature near the surface of the film after a sample including the film is illuminated with a beam of light. This can be accomplished by modulating the beam of light at a selected modulation frequency and measuring the amplitude of the sound waves created in the gas near the surface of the sample as a result of the repetitive heating and cooling of the surface. The amplitude of the sound signal will be directly proportional to the thermal resistivity of the thin film, provided that the modulation frequency is selected within an appropriate range. In a preferred embodiment of the invention, a portion of the thin film is removed from (or not deposited on) the substrate and the entire surface of the substrate, including the portion coated with the thin film and the bare half is coated with a layer of covering material, such as graphite or metal. The amplitude of the sound signal generated by the layer of covering material on the bare substrate surface is then subtracted from the amplitude of the signal generated by the two layer side of the substrate. The remainder is essentially equal to the portion of the amplitude contributed by the thermal resistivity of the thin film itself. In this manner, even transparent thin films which do not heat appreciably upon illumination can be evaluated.