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:
Mar. 28, 2006
Filed:
Sep. 15, 2004
Antonio Orozco, Washington, DC (US);
Elena Talanova, Greenbelt, MD (US);
Alfred B. Cawthorne, Beltsville, MD (US);
Lee Knauss, Bowie, MD (US);
Thirumalai Venkatesan, Washington, DC (US);
Antonio Orozco, Washington, DC (US);
Elena Talanova, Greenbelt, MD (US);
Alfred B. Cawthorne, Beltsville, MD (US);
Lee Knauss, Bowie, MD (US);
Thirumalai Venkatesan, Washington, DC (US);
Neocera, Inc., Beltsville, MD (US);
Abstract
Circuit flaws in microelectronic circuitry present regions of high resistance in which a current distribution deviates from that of a defect-free circuit. The altered current distribution emits a correspondingly altered magnetic field in accordance with Ampere's Law. When compared with the magnetic field of a defect-free circuit, the anomaly in the magnetic field of the defective device is detected and the location of the circuit flaw may be determined therefrom. As the anomaly in the magnetic field is very small in magnitude, a sensitive magnetic microscope is utilized to obtain images of the magnetic fields of a defect-free reference device and a device-under-test. The distance between the magnetic sensor and the devices being scanned is precisely controlled to minimize influences of scanning distance on the difference in measured magnetic field strength. Comparative image analysis reveals the location of the circuit flaw. Maximal image registration through image interpolation, displacement and resampling optimizes the comparative image analysis.