Hardware Probing Interface and Test Robustness

Hardware interface integrity test of an electronic product and validation of a tester’s probing needles is an integral part of a test scenario. Integrity testing is based on a current voltage characteristic measurement, when a small voltage and ( or ) current stimuli are applied to the product pads including power supply circuitry pads, so that the product is not normally powered on. Needles validation should be used as a part of a self test maintenance scenario designed to predict deterioration of product probing. Introduction. The set of a test fixture needle probes and connectors are used for Unit Under Test (UUT) and a tester ports interconnect implementation. As a rule it is supposed that UUT probing is reliable, so that the portion of test failures the root cause of which is a probing deterioration is too small to be taken into account. Real world is more complicated. Sometimes UUT does not pass test procedures because of the probing deterioration. The result is the UUT testing failure, while detailed analysis of a failed UUT features finds no problem: it is Not Troubles Found (NTF) issue. It occurs due to the fact that the probing validity is not under the tester’s monitoring and control. Mature testing relies on an assumption that the UUT mounted in a test fixture has reliable interconnect with the control and the sensing ports of the tester and the probing validity is under the supervision of the testing routine. NTF failure risk should be minimized as much as possible because it takes an additional time to run retests and analyze the status of UUT: whether it really failed or not.