US 6,100,815 AGranted

Compound switching matrix for probing and interconnecting devices under test to measurement equipment

AssigneeElectro Scientific Industries, Inc.

InventorRobert M. Pailthorp

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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.

Claims11

Dependent claims

A compound switching matrix apparatus for interconnecting a set of devices that each include first and second contacts to first and second sets of terminals on a measurement system, comprising:

a first set of probes contacting the first contacts on the set of devices;
a second set of probes contacting the second contacts on the set of devices;
first set of probe matrix relays mounted on a first circuit board for selectively interconnecting the first set of probes to a first set of inter-matrix conductors;
a second set of probe matrix relays mounted on a second circuit board for selectively interconnecting the second set of probes to a second set of inter-matrix conductors, the first and second circuit boards electrically isolating the first set of probe matrix relays and inter-matrix conductors from the second set of probe matrix relays and inter-matrix conductors:
a first set of configuration matrix relays selectively interconnecting the first set of terminals on the measurement system to the first set of inter-matrix conductors;
a second set of configuration matrix relays selectively interconnecting the second set of terminals on the measurement system to the second set of inter-matrix conductors;
and
a laser that cooperates with the measurement system to laser trim a device in the set of devices to a predetermined value.

5 more elements

Dependencies are inferred from the claim text.