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. 24, 2020
Filed:
Nov. 28, 2017
Ntn Corporation, Osaka, JP;
Hiroaki Ohba, Iwata, JP;
NTN CORPORATION, Osaka, JP;
Abstract
There is provided a method of measuring a film thickness of a transparent material on a substrate. A first object (transparent material) is applied onto a first substrate surface, and a second object (transparent material) is applied onto a second substrate surface. The method includes: measuring a first relative height of a front surface of the first object with respect to the first substrate surface at a position without the first object; measuring a second relative height of the front surface with respect to a back surface of the first object; and calculating a refractive index of the transparent material, based on the first relative height and the second relative height. The method includes measuring a film thickness of the second object, using a third relative height of a front surface of the second object with respect to a back surface of the second object and the calculated refractive index.