Semiconductor continuity test using PXI-based dynamic digital instrumentation with PMU capabilities
01 May 2021
Marvin Test Solutions_Semiconductor continuity test using PXI-based dynamic digital instrumentation with PMU capabilities
One of the fundamental tenets of functional test is to validate the operation & characteristics of the device-under-test without inflicting damage during the process – and this includes some of the most basic tasks, such as applying power.
The full version of this article was originally featured in EPDT's 2021 PXI for T&M supplement, included in the May 2021 issue of EPDT magazine [read the digital issue]. And sign up to receive your own copy each month.
Prior to testing the functionality of semiconductor devices, one should verify the structural integrity of the device, as well as confirm connections to the test system. As Jon Semancik, Director of Marketing at aerospace T&M company, Marvin Test Solutions explains here, DC parametric measurement units (PMUs), which are commonly used to perform DC characterisation tests on semiconductor devices, are also ideal for this type of verification.
Many dynamic digital instruments incorporate PMU functionality on a per pin basis, allowing each digital channel to be independently programmed to force voltage and measure current, or force current and measure voltage. Furthermore, PXI-based dynamic digital instruments provide exceptional flexibility, offering users a straightforward path to easily upgrade current digital capabilities or to expand channel count in existing test systems.
The first step in the test process is to determine if the device-under-test (DUT) is connected to the dynamic digital test resources. This test is called the continuity test, and it verifies continuity between the tester and DUT by detecting the electrostatic discharge (ESD) diode found on IC pins. Tester to DUT continuity is measured by forcing a small current onto the DUT pins, and measuring the presence or absence of a voltage. This utilises the force current, measure voltage (FIMV) capability of the dynamic digital PMU.
The ESD protection diode is a semiconductor device, and the voltage developed across it when a current flows is consistent with the voltage drop across a typical semiconductor junction. If the ESD diode is not present or, in the case of continuity tests, if the tester is not connected to the DUT pin, current will not flow through the ESD diode and the voltage will be inconsistent with semiconductor junction voltage drops. If the ESD diode is defective, other voltage anomalies can also be detected; for example “0” volts measured across an ESD diode indicates a condition where the diode is shorted.
The first step in the test process involves defining the system configuration within the software application, where the number of DUTs installed in the test fixture, and their respective pin counts, will be defined programmatically...
Read the full article in EPDT's May 2021 digital issue...
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