ESD Stress Test Models Jos D Sancho NASA

ESD Stress Test Models José D. Sancho NASA Workmanship Standards 1 12/7/2020

Introduction General Comments l What is an ESD Sensitivity Level? l How is it obtained? l Why is it important to the user? l Why different test models? l How we can reduce ESD related failures l NASA Workmanship Standards 2 12/7/2020

Agenda l l l The human body model (HBM) The machine model (MM) The charge device model (CDM) – Robotic (Real) CDM (R-CDM) – Socketed CDM (SDM) l l Damage differences between models Transmission Line Pulse (TLP) stress testing Reasons for CDM/TLP current emphasis Questions NASA Workmanship Standards 3 12/7/2020

Overview ESD standard test models define the ESD sensitivity level of electronic parts. l Their Significance to the different sensitivity levels used in industry. l FA recognition of the model responsible for an ESD failure event. l ESD Models: (differences & interrelation) NASA Workmanship Standards HBM M M TLP CDM 4 12/7/2020

The Human Body Model (HBM) l 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 5 12/7/2020

HBM Test Circuit 100 Meg SW 1 1. 5 K SW 2 HV Supply DUT 100 pf IPS IPR 500 Ω 10 K-10 Meg Courtesy of ESDA Basic HBM Test Circuit NASA Workmanship Standards 6 12/7/2020

HBM Waveforms. Older waveform ANSI/ESD STM 5. 1 -2001 Current Waveform through a shorting wire ANSI/ESD STM 5. 1 -2001 Stress Waveform Used for HBM ESD Testing NASA Workmanship Standards 7 12/7/2020

Typical HBM Generated Failures 100 X 2000 X Courtesy of JPL NASA Workmanship Standards Scott M. Hull NASA/GSFC 8 12/7/2020

The Machine Model (MM) l l l 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 9 12/7/2020

Original MM Circuit & Waveform 100 Meg 500 n. H SW 1 SW 2 HV Supply NASA Workmanship Standards 200 pf 10 K 10 Meg DUT 10 12/7/2020

ESDA Machine Model Circuit 100 Meg SW 1 SW 2 HV Supply 200 pf NASA Workmanship Standards 10 K-10 Meg Ip. S DUT Short Ip. R 500 Ω 11 12/7/2020

ESDA MM Test Waveforms ANSI/ESD STM 5. 2 -1999 400 v discharge through a shorting wire NASA Workmanship Standards ANSI/ESD STM 5. 2 -1999 400 v discharge through a 500 Ω resistor 12 12/7/2020

Typical MM ESD Stress Failure Scott M. Hull NASA/GSFC NASA Workmanship Standards 13 12/7/2020

The Charge Device Model (CDM) Simulates Electrostatic Charge transfer from a Device. l Two sub-models are used R-CDM & SDM l Test repeatability between Test-Sets has been a problem. l Per ESDA Statistics, 90% of all field failures are caused by CDM ESD events. l Failures are typically at the core of the Device l NASA Workmanship Standards 14 12/7/2020

Charge Device Model Circuits Device with Multiple Discharge Paths Device with One Point Discharge Sw 1 DUT Sw 1 Rd Rc DUT Rd 1 Ld Rc Ld 1 Rd 2 Ld 2 Rdn Ldn Cd Cd 1 Rc = Resistance to Ground. NASA Workmanship Standards Rd , L d , Cd = Cd 2 Cdn Resistance, Inductance & Capacitance In the Discharge Path. 15 12/7/2020

ESDA CDM Test Waveform ANSI/ESD STM 5. 3. 1 -1999 Waveform for the verification Modules using a 3. 5 GHz BW NASA Workmanship Standards 16 12/7/2020

Typical CDM generated failures 4600 x 8600 x Courtesy of JPL NASA Workmanship Standards Courtesy of JPL 17 12/7/2020

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 18 12/7/2020

Models Comparisons ESD Models ZD RC CD (pf) LD (μH) ΕS (μJ) 5τ (ηs) Pave (W) IPS (A) Vc = 200 V Typ. # Req # Typ # ½CV 2 5 Re. C Ε/τeff V/Re HBM 0 1500 100 0 2 750 3 0. 13 MM 55 2 200 5. 0 E-07 4 160 25 3. 5 CDM 42 25 15 1. 0 E-08 0. 3 5 30 3 ESD Models ZD RC CD LD ΕS in μJ 5τ in ηs Pave (W) IPS Vc = 1000 V Typ. # Req # Typ # ½CV 2 5 Re. C Ε/τeff V/Re HBM 0 1500 100 0 50 750 ~67 0. 67 MM 55 2 200 5. 0 E-07 100 160 625 17. 5 CDM 42 25 15 1. 0 E-08 7. 5 5 >750 15 Courtesy of ESDA NASA Workmanship Standards 19 12/7/2020

Transmission Line Pulse (TLP) Used By IC Designers since 1985 to evaluate ESD protection schemes. l Simulates HBM with very short pulses. l Allows non-destructive & latch-up issues testing. l Provides better results on a controlled simulation of the SDM. l NASA Workmanship Standards 20 12/7/2020

TLP Design Methodologies Current Source l Time Domain Reflectometer l Time Domain Transmission l Time Domain Reflection and Transmission l NASA Workmanship Standards 21 12/7/2020

Current Source TLP ANSI/ESD SP 5. 5. 1 -2004 NASA Workmanship Standards 22 12/7/2020

Time Domain Reflectometer TLP ANSI/ESD SP 5. 5. 1 -2004 NASA Workmanship Standards 23 12/7/2020

Time Domain Transmission TLP ANSI/ESD SP 5. 5. 1 -2004 NASA Workmanship Standards 24 12/7/2020

TDR&T TLP ANSI/ESD SP 5. 5. 1 -2004 NASA Workmanship Standards 25 12/7/2020

Summary Models establish Benchmarks for ESD Sensitivity. l Different Models are used under different environments. l Models provide help to prevent and analyze ESD Failures l Please send feedback to: jsancho. 1@pop 300@nasa. gsfc. gov l NASA Workmanship Standards 26 12/7/2020

Where to Get More Information WEB searches under “ESD Models” l ESDA publications l Consulting services provide Advice on tough ESD problems and Solutions. l NASA Workmanship Standards 27 12/7/2020

References 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. ANSI/ESD STM 5. 1 -2001 ESD Sensitivity Testing (HBM) ANSI/ESD STM 5. 2 -1999 ESD Sensitivity Testing (MM) ANSI/ESD STM 5. 3. 1 -1999 ESD Sensitivity Testing (CDM) ANSI/ESD SP 5. 2. 2 -2004 ESD Sensitivity Testing (SDM) ANSI/ESD SP 5. 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/cemag. com/archive/01/03/0103 CE_046. html NASA Workmanship Standards 28 12/7/2020