ATE Glossary [I - P]

ICT - In-Circuit Test(er). A form of test or tester where a bed of nails fixture is used to connect to nodes on the board under test. In this way measurements of individual components can be made “in-circuit” to ensure they are of the correct value / operational and that there no short or open circuits present.

JTAG – Joint Test Action Group. The group that originally investigate new methods of testing assemblies to which limited access was available. The resulting test methodology was boundary scan (IEEE 1149.1) and as a result this term is often synonymous with boundary scan.

MDA - Manufacturing Defect Analyser. A limited form of in-circuit test that only tests for manufacturing defects – typically short and open circuits.

MTBF – Mean Time Between Failures. The average time that a device or unit works without a failure.

MTTR – Mean Time To Repair. The average time that it takes to repair a failure.

MUX – Multiplexer. A set of mechanical or semiconductor switches arranged to enable one line from many to be selected and routed trough to the output.

MVI – Manual Visual Inspection. Inspection performed by a human operator.

Nail – The spring loaded metal pin used in a bed of nails fixture to make contact with a node on a board or other assembly being tested.

Node – The point on a circuit where two or more components of other elements meet.

Node Name – The name by which a node is known by a test programme.

Non-Observable Fault – A fault for which the effects may not be seen at any of the external terminals of the assembly or device.

Parametric fault – A fault that is caused by component value changes that results in a output level change.

Parametric Test – A test that measures the value of a parameter on the output or a particular point of an assembly.

Pattern – A data applied to a DUT as part of a test. This will enable the DUT to respond in a particular fashion.

Pattern Vector – The data applied to a DUT for one test cycle.

Pogo Pin – The more exact term for a particular type of nail used on a test fixture to make contact with the UUT. It consists of two small tubular sections joined together with an internal spring and with a contactor formed on the end of the smaller tube.