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:
Aug. 08, 2000
Filed:
Dec. 24, 1997
Robert M Pailthorp, Portland, OR (US);
Electro Scientific Industries, Inc., Portland, OR (US);
Abstract
A compound switching matrix (30) operates in cooperation with a resistance measuring system (20) and a laser (22) to quickly and accurately trim resistors (12) to predetermined values while they are being measured. The compound switching matrix is implemented with dry reed relays (34-81, 101-164) and includes a probe switching matrix (90-97) and a configuration matrix (32) that reduce the average number of relay contacts required per probe to implement two-, three-, and four-terminal measurements with or without guarding. Moreover, the separate probe switching and measurement configuration matrices effectively separate the high and low sides of the measurement to reduce the effects of stray resistances and capacitances on measurement speed and accuracy. A switchable grounding configuration (82-89) further improves measurement accuracy. The compound switching matrix of this invention enables sequential resistance measurements of individual resistors in the array, with two-, three-, and four-terminal measurement configurations being adapted to resistors having values ranging from less than 0.1 ohm to greater than 100 Megohms.