ESD Stress Test Models José D. Sancho NASA Workmanship Standards 4/1/2017

Introduction General Comments What is an ESD Sensitivity Level? How is it obtained? Why is it important to the user? Why different test models? How we can reduce ESD related failures NASA Workmanship Standards 4/1/2017

Agenda The human body model (HBM) The machine model (MM) The charge device model (CDM) Robotic (Real) CDM (R-CDM) Socketed CDM (SDM) Damage differences between models Transmission Line Pulse (TLP) stress testing Reasons for CDM/TLP current emphasis Questions NASA Workmanship Standards 4/1/2017

(differences & interrelation) Overview ESD standard test models define the ESD sensitivity level of electronic parts. Their Significance to the different sensitivity levels used in industry. FA recognition of the model responsible for an ESD failure event. HBM MM ESD Models: (differences & interrelation) TLP CDM NASA Workmanship Standards 4/1/2017

The Human Body Model (HBM) Simulates an Electrostatic Discharge from the human body to a device (e.g. electronic component). Most commonly used model Best understood by operators Best controlled by Equipment and Training Courtesy of Botron Co. NASA Workmanship Standards 4/1/2017

HBM Test Circuit Basic HBM Test Circuit Courtesy of ESDA 100 Meg SW1 1.5 K SW2 DUT IPS IPR HV Supply 500 Ω 100 pf 10 K-10 Meg Courtesy of ESDA Basic HBM Test Circuit NASA Workmanship Standards 4/1/2017

HBM Waveforms Stress Waveform Used for HBM ESD Testing Older waveform. ANSI/ESD STM5.1-2001 Current Waveform through a shorting wire ANSI/ESD STM5.1-2001 ANSI/ESD STM5.1-2001 Stress Waveform Used for HBM ESD Testing NASA Workmanship Standards 4/1/2017

Typical HBM Generated Failures 100X 2000X Scott M. Hull NASA/GSFC Courtesy of JPL NASA Workmanship Standards 4/1/2017

The Machine Model (MM) Originated in Japan Discharge from Equipment or Small Tools to a Device Simulates some ESD events in Automatic Equipment Repetitive, faster and more severe than the HBM Mostly used in the design of Automatic Handling Equipment and ESD-safe tools NASA Workmanship Standards 4/1/2017

Original MM Circuit & Waveform 100 Meg 500 nH SW1 SW2 DUT HV Supply 200 pf 10 K-10 Meg NASA Workmanship Standards 4/1/2017

ESDA Machine Model Circuit HV Supply SW1 SW2 100 Meg 10 K-10 Meg 200 pf DUT 500 Ω Short IpS IpR NASA Workmanship Standards 4/1/2017

ESDA MM Test Waveforms ANSI/ESD STM5.2-1999 ANSI/ESD STM5.2-1999 400 v discharge through a shorting wire 400 v discharge through a 500 Ω resistor NASA Workmanship Standards 4/1/2017

Typical MM ESD Stress Failure Scott M. Hull NASA/GSFC NASA Workmanship Standards 4/1/2017

The Charge Device Model (CDM) Simulates Electrostatic Charge transfer from a Device. Two sub-models are used R-CDM & SDM Test repeatability between Test-Sets has been a problem. Per ESDA Statistics, 90% of all field failures are caused by CDM ESD events. Failures are typically at the core of the Device NASA Workmanship Standards 4/1/2017

Charge Device Model Circuits Device with One Point Discharge Device with Multiple Discharge Paths Sw1 DUT Rc Rd1 Rd2 Rdn Ld1 Ld2 Ldn Sw1 DUT Rd Ld Rc Cd Cd1 Cd2 Cdn Rc = Resistance to Ground. Rd, Ld, Cd = Resistance, Inductance & Capacitance In the Discharge Path. NASA Workmanship Standards 4/1/2017

Waveform for the verification Modules using a 3.5 GHz BW ESDA CDM Test Waveform ANSI/ESD STM5.3.1-1999 Waveform for the verification Modules using a 3.5 GHz BW NASA Workmanship Standards 4/1/2017

Typical CDM generated failures 4600x 8600x Courtesy of JPL Courtesy of JPL NASA Workmanship Standards 4/1/2017

Typical CDM Generated Failure Courtesy of Frederick Felt GSFC Part Analysis Lab. ESD event (~1 KV) shown at arrow after parallel Polishing NASA Workmanship Standards 4/1/2017

Models Comparisons Courtesy of ESDA ESD Models ZD RC CD (pf) LD (μH) ΕS (μJ) 5τ (ηs) Pave (W) IPS (A) Vc = 200 V Typ. # Req # Typ # ½CV2 5ReC Ε/τeff V/Re HBM 1500 100 2 750 3 0.13 MM 55 200 5.0E-07 4 160 25 3.5 CDM 42 15 1.0E-08 0.3 5 30   CD LD ΕS in μJ 5τ in ηs IPS Vc = 1000 V Typ.# Req # Typ # 50 ~67 0.67 625 17.5 7.5 >750 Courtesy of ESDA NASA Workmanship Standards 4/1/2017

Transmission Line Pulse (TLP) Used By IC Designers since 1985 to evaluate ESD protection schemes. Simulates HBM with very short pulses. Allows non-destructive & latch-up issues testing. Provides better results on a controlled simulation of the SDM. NASA Workmanship Standards 4/1/2017

TLP Design Methodologies Current Source Time Domain Reflectometer Time Domain Transmission Time Domain Reflection and Transmission NASA Workmanship Standards 4/1/2017

Current Source TLP ANSI/ESD SP5.5.1-2004 NASA Workmanship Standards 4/1/2017

Time Domain Reflectometer TLP ANSI/ESD SP5.5.1-2004 NASA Workmanship Standards 4/1/2017

Time Domain Transmission TLP ANSI/ESD SP5.5.1-2004 NASA Workmanship Standards 4/1/2017

TDR&T TLP ANSI/ESD SP5.5.1-2004 NASA Workmanship Standards 4/1/2017

Summary Models establish Benchmarks for ESD Sensitivity. Different Models are used under different environments. Models provide help to prevent and analyze ESD Failures Please send feedback to: jsancho.1@pop300@nasa.gsfc.gov NASA Workmanship Standards 4/1/2017

Where to Get More Information WEB searches under “ESD Models” ESDA publications Consulting services provide Advice on tough ESD problems and Solutions. NASA Workmanship Standards 4/1/2017

References ANSI/ESD STM5.1-2001 ESD Sensitivity Testing (HBM) ANSI/ESD STM5.2-1999 ESD Sensitivity Testing (MM) ANSI/ESD STM5.3.1-1999 ESD Sensitivity Testing (CDM) ANSI/ESD SP5.2.2-2004 ESD Sensitivity Testing (SDM) ANSI/ESD SP5.5.1-2004 ESD Sensitivity Testing (TPL) Scott M. Hull, “ESD Failures in Thin-Film Resistors” NASA/Goddard Space Flight Center http://qa.jpl.nasa.gov/esd/ http://esdsystems.com/whitepapers/ http://www.semiconfareast.com http://www.ce-mag.com/archive/01/09/henry.html http://www.ce-mag.com/ce-mag.com/archive/01/03/0103CE_046.html NASA Workmanship Standards 4/1/2017