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:
Jun. 01, 2021
Filed:
Dec. 16, 2019
Fei Efa, Inc., Fremont, CA (US);
Christian Schmidt, Halle, DE;
FEI EFA, Inc., Fremont, CA (US);
Abstract
Localizing hot spots in multi layered device under test (DUT) by using lock-in thermography (LIT) where plural hot spots of electrical circuits are buried in the DUT at different depth layers from a bottom layer to a top layer, comprises applying test signals of multiple frequencies to the electrical circuits of the DUT for exciting the hot spots; imaging a top surface of the top layer of the DUT at timed intervals to obtain IR images of the DUT while the test signal is applied to the electrical circuits wherein the images are in correlation to a propagation of heat from the hot spots in the DUT; detecting the thermal response signals at the timed intervals from the images taken from the DUT; and determining changes in the appearance of hot spot images on the top surface of the DUT in relation to the frequencies of the thermal response signals.