Failure Detection with HMM Waveforms Kathleen Muhonen (1), Jeffrey Dunnihoo (2), Evan Grund (3), Nate Peachey (4), Anguel Brankov (5) (1) Penn State Erie, The Behrend College, 5101 Jordan Road, Erie, PA 16563 USA tel.: 814-898-6468, fax: 814-898-6215, e-mail: kmuhonen@psu.edu (2) California Micro Devices, P.O. Box 413 Bertram, TX 78605 USA (3) Grund Technical Solutions, 5932 Amapola Drive, San Jose, CA 95129 USA (4) RFMD, 7628 Thorndike Road, Greensboro, NC 27409 USA (5) California Micro Devices, 490 N. McCarthy Blvd. #100, Milpitas, CA 95035 Abstract - HMM data illustrates the usefulness of collecting current pulse waveforms during HMM testing. Waveforms revealed failures before leakage measurements would show device failure. With capacitively coupled devices, Time Domain Reflectometry, (TDR), can be used to detect part failures in addition to extracting this information from HMM pulse waveforms. I. Introduction Human Metal Model (HMM) testing [1] is the application of the IEC 61000-4-2 waveform [2] to a component. It is becoming more prevalent for original equipment manufacturers to require testing of individual components with the IEC waveform [3], [4]. The work presented in this paper uses an HMM pulser (50 ohm source [5]) or an ESD gun to generate an IEC-61000-4-2 compliant waveform for testing individual components. As with any type of ESD testing, failure levels need to be determined and that can be a challenge depending on the type of part under test and the test setup. A DC leakage measurement is commonly used after ESD stresses to determine if a part has failed. The test is usually applied at a low enough voltage such that no internal circuitry of the DUT turns on. The problem associated with a DC leakage test is components can fail a functional test long before they will fail a DC leakage test. In addition, for I/O interfaces that are capacitively or transformer coupled in a system, performing leakage measurements can be challenging. One method requires the coupling component(s) to be bypassed for a DC leakage test. A test setup that allows such switching may significantly distort the ESD stress pulses. What is needed is an AC method of detecting DUT physical damage. Time Domain Reflectometry, (TDR), measures impedance versus time by analyzing transmitted and reflected pulses and can be used for failure detection when DC measurement is not possible. Although useful when DC leakage measurements cannot be made, TDR measurements require special equipment and operator interpretation to reveal failures. TDR has a more limited measurement range and sensitivity than DC leakage instrumentation; but hard failures usually produce large changes of DUT impedance which can be measured. A very fast transmission line pulser (VF-TLP) and some network analyzers can also measure with the technique as will be demonstrated. II. Measurement Techniques A. Test Set-Up In this work a 50 ohm HMM pulser from Grund Technical Solutions and several ESD guns were used to generate the IEC-like waveform. A typical waveform from the 50 ohm HMM pulser is shown in Figure 1.