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Measurement of Propagation Delay to Each Probe Tip of Automated Test Equipment

IP.com Disclosure Number: IPCOM000103418D
Original Publication Date: 1990-Nov-01
Included in the Prior Art Database: 2005-Mar-17
Document File: 1 page(s) / 39K

Publishing Venue

IBM

Related People

McCarthy, PF: AUTHOR

Abstract

By measuring propagation delay from each probe tip to a tester, variations in delay of test signals arriving at a device under test are reduced, thus improving device yield.

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This is the abbreviated version, containing approximately 100% of the total text.

Measurement of Propagation Delay to Each Probe Tip of Automated Test Equipment

      By measuring propagation delay from each probe tip to a tester,
variations in delay of test signals arriving at a device under test
are reduced, thus improving device yield.

      Referring to the figure, a node plate comprised of a first
conductive surface 2 and a second conductive surface 4 on either side
of insulator 6, e.g., gold plated, two-sided copper printed circuit
board, is attached via coaxial cable 8 to a pulse source 10.  Damping
resistor 12 is connected to conductive surface 2 and to the central
conductor of cable 8.  The outer coaxial shield is connected to
conductive surface 4.  All tester probe tips 14 (only one shown) are
placed simultaneously in contact with conductive surface 2. Standard
connections and cabling connect probe tips 14 to edge detector 16
normally used for propagation delay measurement and skew correction
in an automatic tester.

      Pulses applied to conductor plate 2 are used in determining
individual channel propagation delay from each probe tip.  An
algorithm, already in use in the tester, corrects tester pulse timing
accordingly.  Thus, variations in channel delay caused by
differences, e.g., line length through connecting boards, etc., are
compensated during testing.

      Disclosed anonymously.