IEC 62396-2:2017

Process management for avionics - Atmospheric radiation effects - Part 2: Guidelines for single event effects testing for avionics systems

IEC 62396-2:2017(E) aims to provide guidance related to the testing of electronic components for purposes of measuring their susceptibility to single event effects (SEE) induced by neutrons generated by cosmic ray interactions in the Earth’s atmosphere (atmospheric neutrons). Since the testing can be performed in a number of different ways, using different kinds of radiation sources, it also shows how the test data can be used to estimate the SEE rate of electronic components and boards due to atmospheric neutrons at aircraft altitudes. Although developed for the avionics industry, this process can be applied by other industrial sectors.

General Information

• Status: Published
• Publication Date: 14-Dec-2017
• ICS: 03.100.50 - Production. Production management
• ICS: 29.060.10 - Wires
• ICS: 31.020 - Electronic components in general
• ICS: 49.060 - Aerospace electric equipment and systems
• Technical Committee: TC 107 - Process management for avionics
• Current Stage: PPUB - Publication issued
• Completion Date: 15-Dec-2017

Standards Content (Sample)

IEC 62396-2
Edition 2.0 2017-12
INTERNATIONAL
STANDARD
colour
inside
Process management for avionics – Atmospheric radiation effects –
Part 2: Guidelines for single event effects testing for avionics systems
IEC 62396-2:2017-12(en)
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IEC 62396-2
Edition 2.0 2017-12
INTERNATIONAL
STANDARD
colour
inside
Process management for avionics – Atmospheric radiation effects –
Part 2: Guidelines for single event effects testing for avionics systems
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 03.100.50; 31.020; 49.060 ISBN 978-2-8322-5098-3

Warning! Make sure that you obtained this publication from an authorized distributor.

® Registered trademark of the International Electrotechnical Commission
---------------------- Page: 3 ----------------------
– 2 – IEC 62396-2:2017 © IEC 2017
CONTENTS

FOREWORD ........................................................................................................................... 4

INTRODUCTION ..................................................................................................................... 6

1 Scope .............................................................................................................................. 7

2 Normative references ...................................................................................................... 7

3 Terms and definitions ...................................................................................................... 7

4 Abbreviated terms ........................................................................................................... 7

5 Obtaining SEE data ......................................................................................................... 9

5.1 Types of SEE data .................................................................................................. 9

5.2 Use of existing SEE data ........................................................................................ 9

5.2.1 General ........................................................................................................... 9

5.2.2 Heavy ion data .............................................................................................. 10

5.2.3 High energy neutron and proton data ............................................................. 10

5.2.4 Thermal neutron data .................................................................................... 11

5.3 Deciding to perform dedicated SEE tests .............................................................. 11

6 Availability of existing SEE data for avionics applications .............................................. 11

6.1 Variability of SEE data .......................................................................................... 11

6.2 Types of existing SEE data that may be used ....................................................... 11

6.2.1 General ......................................................................................................... 11

6.2.2 Sources of data, proprietary versus published data ........................................ 13

6.2.3 Data based on the use of different sources .................................................... 14

6.2.4 Ground level versus avionics applications ...................................................... 19

6.3 Sources of existing data ........................................................................................ 19

7 Considerations for SEE testing ...................................................................................... 22

7.1 General ................................................................................................................. 22

7.2 Selection of hardware to be tested ........................................................................ 22

7.3 Selection of test method ....................................................................................... 22

7.4 Selection of facility providing energetic particles ................................................... 23

7.4.1 Radiation sources .......................................................................................... 23

7.4.2 Spallation neutron sources ............................................................................ 24

7.4.3 Monoenergetic and quasi-monoenergetic beam sources ................................ 25

7.4.4 Thermal neutron sources ............................................................................... 26

7.4.5 Whole system and equipment testing ............................................................. 27

8 Converting test results to avionics SEE rates ................................................................. 28

8.1 General ................................................................................................................. 28

8.2 Use of spallation neutron source ........................................................................... 28

8.3 Use of SEU cross-section curve over energy ........................................................ 29

8.4 Measured SEU rates for different accelerator-based neutron sources ................... 32

8.5 Influence of upper neutron energy on the accuracy of calculated SEE rates –

Verification and compensation .............................................................................. 32

Annex A (informative) Sources of SEE data published before the year 2000 ........................ 34

Bibliography .......................................................................................................................... 35

Figure 1 – Comparison of Los Alamos, TRIUMF and ANITA neutron spectra with

terrestrial/avionics neutron spectra (JESD89A and IEC 62396-1) .......................................... 15

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IEC 62396-2:2017 © IEC 2017 – 3 –

Figure 2 – Variation of high energy neutron SEU cross-section per bit as a function of

electronic component feature size for SRAM and SRAM arrays in FPGA and

microprocessors ................................................................................................................... 17

Figure 3 – Percentage fraction of SEU rate from atmospheric neutrons contributed by

neutrons with E < 10 MeV ..................................................................................................... 18

Figure 4 – Comparison of monoenergetic SEU cross-sections with Weibull and piece-

wise linear fits ....................................................................................................................... 31

Table 1 – Sources of existing data (published after 2000) ..................................................... 20

Table 2 – Spectral distribution of neutron energies ............................................................... 32

Table A.1 – Sources of existing SEE data published before the year 2000 ............................ 34

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– 4 – IEC 62396-2:2017 © IEC 2017
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
PROCESS MANAGEMENT FOR AVIONICS –
ATMOSPHERIC RADIATION EFFECTS –
Part 2: Guidelines for single event effects
testing for avionics systems
FOREWORD

1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising

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patent rights. IEC shall not be held responsible for identifying any or all such patent rights.

International Standard IEC 62396-2 has been prepared by IEC technical committee 107:

Process management for avionics.

This second edition cancels and replaces the first edition published in 2012. This edition

constitutes a technical revision.

This edition includes the following significant technical changes with respect to the previous

edition.

a) improvements and changes to test facilities have been added in Clause 7, which includes

new facilities at TSL, TRIUMF and ChipIr,
b) links with IEC 60749-38 and IEC 60749-44 are made in 7.1.
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IEC 62396-2:2017 © IEC 2017 – 5 –
The text of this International Standard is based on the following documents:
FDIS Report on voting
107/316/FDIS 107/318/RVD

Full information on the voting for the approval of this International Standard can be found in

the report on voting indicated in the above table.

This document has been drafted in accordance with the ISO/IEC Directives, Part 2.

A list of all parts in the IEC 62396 series, published under the general title Process

management for avionics – Atmospheric radiation effects, can be found on the IEC website.

The committee has decided that the contents of this document will remain unchanged until the

stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to

the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
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IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates

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colour printer.
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– 6 – IEC 62396-2:2017 © IEC 2017
INTRODUCTION

This industry-wide international standard provides additional guidance to avionics systems

designers, electronic equipment manufacturers and their customers for determining the

susceptibility of electronic components to single event effects. It expands on the information

and guidance provided in IEC 62396-1:2016.

Guidance is provided on the use of existing single event effects (SEE) data, sources of data

and the types of accelerated radiation sources used. Where SEE data is not available

considerations for testing are introduced, including suitable radiation sources for providing

avionics SEE data. The conversion of data obtained from differing radiation sources into

avionics SEE rates is detailed.
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IEC 62396-2:2017 © IEC 2017 – 7 –
PROCESS MANAGEMENT FOR AVIONICS –
ATMOSPHERIC RADIATION EFFECTS –
Part 2: Guidelines for single event effects
testing for avionics systems
1 Scope

This part of IEC 62396 aims to provide guidance related to the testing of electronic

components for purposes of measuring their susceptibility to single event effects (SEE)

induced by neutrons generated by cosmic ray interactions in the Earth’s atmosphere

(atmospheric neutrons). Since the testing can be performed in a number of different ways,

using different kinds of radiation sources, it also shows how the test data can be used to

estimate the SEE rate of electronic components and boards due to atmospheric neutrons at

aircraft altitudes.

Although developed for the avionics industry, this process can be applied by other industrial

sectors.
2 Normative references

The following documents are referred to in the text in such a way that some or all of their

content constitutes requirements of this document. For dated references, only the edition

cited applies. For undated references, the latest edition of the referenced document (including

any amendments) applies.

IEC 62396-1:2016, Process management for avionics – Atmospheric radiation effects – Part 1:

Accommodation of atmospheric radiation effects via single event effects within avionics

electronic equipment
3 Terms and definitions

For the purposes of this document, the terms and definitions given in IEC 62396-1 apply.

ISO and IEC maintain terminological databases for use in standardization at the following

addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
4 Abbreviated terms
ANITA Atmospheric-like Neutrons from thIck TArget (TSL, Sweden)
BL1A, BL1B, BL2C beam line designations at the TRIUMF facility (Canada)
BPSG borophosphosilicate glass
ChipIr beam line at the ISIS neutron source facility (Rutherford Appleton
Laboratory, UK)
CIAE China Institute of Atomic Energy
CMOS complementary metal oxide semiconductor
COTS commercial off-the-shelf
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– 8 – IEC 62396-2:2017 © IEC 2017
CUP close user position, neutron beam facility (TSL, Sweden)
CYRIC CYclotron and Radio Isotope Center (Tohoku University, Japan)
D-D deuterium-deuterium
DRAM dynamic random access memory
D-T deuterium-tritium
DUT device under test
E energy
EEPROM electrically erasable programmable read only memory
EMC electromagnetic compatibility
EPROM electrically programmable read only memory
ESA European Space Agency
eV electron volt
FinFET fin field effect transistor
FIT failures in time (failures in 10 h)
FPGA field programmable gate array
GeV giga electron volt
GNEIS Gatchina Neutron Spectrometer (Russia)
GSFC Goddard Space Flight Center
GV giga volt (rigidity unit)
IBM International Business Machines
IC integrated circuit
ICE Irradiation of Chips and Electronics
IEEE Trans. Nucl. Sci. IEEE Transactions on Nuclear Science
ISIS neutron beam source (Rutherford Appleton Laboratory, UK)
IUCF Indiana University Cyclotron Facility (USA)
JEDEC JEDEC Solid State Technology Association
JESD JEDEC standard
JPL Jet Propulsion Laboratory
LANSCE Los Alamos Neutron Science Center (USA)
LET linear energy transfer
LETth linear energy transfer threshold
MBU multiple bit upset (in the same word)
MCU multiple cell upset
MeV mega electron volt
NASA National Aeronautical and Space Agency
PCN product change notification
PIF Proton Irradiation Facility (TRIUMF, Canada)
PNPI Petersburg Nuclear Physics Institute (Russia)
PSG phosphosilicate glass
QMN quasi-monoenergetic neutron
RADECS RADiations, Effects on Components and Systems
RAL Rutherford Appleton Laboratory (UK)
RAM random access memory
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IEC 62396-2:2017 © IEC 2017 – 9 –
RCNP Research Center of Nuclear Physics (Osaka, Japan)
SBU single bit upset
SDRAM synchronous dynamic random access memory
SEB single event burn-out
SEE single event effect
SEFI single event functional interrupt
SEGR single event gate rupture
SEL single event latchup
SEP solar energetic particles
SER soft error rate
SET single event transient
SEU single event upset
SHE single event induced hard error
SRAM static random access memory
SW software
TID total ionizing dose
TNF TRIUMF neutron facility (TRIUMF, Canada)
TRIUMF neutron beam source (Vancouver, Canada)
TSL Theodor Svedberg Laboratory (Uppsala, Sweden)
WNR Weapons Nuclear Research (Los Alamos, USA)
5 Obtaining SEE data
5.1 Types of SEE data

The type of SEE data available can be viewed from many different perspectives. As indicated,

the SEE testing can be performed using a variety of radiation sources, all of which can induce

single event effects in electronic components. In addition, many tests are performed on

individual electronic components, but some tests expose an entire single board computer to

radiation fields that can induce SEE. However, a key discriminator is deciding on whether

existing SEE data that may be used is available, or whether there really is no existing data

and therefore a SEE test on the electronic component or board of interest has to be carried

out.
5.2 Use of existing SEE data
5.2.1 General

The simplest solution is to find previous SEE data on a specific electronic component. Data

may be available on SEE caused by heavy ions, protons, high energy neutrons, or thermal

neutrons. Heavy ion data is normally only applicable to space applications, where direct

ionization by the primary cosmic ray flux is of concern. However, heavy ion data can be useful

for screening purposes, as described in 5.2.2. Proton data is usually also gathered for space

applications, where primary cosmic rays and trapped particles are of concern. However, high

energy protons provide a good proxy for neutrons in SEE measurements, as they undergo

very similar nuclear interactions with electronic component materials. Therefore, both existing

neutron data and existing proton data may be applicable to the evaluation of SEE rates in a

device of interest, as described in 5.2.3. Low-energy (“thermal”) neutrons can also cause SEE

in some electronic components but such data is only available on a very small number of

electronic components (see 5.2.4) and it involves neutron interactions with boron-10 rather

than silicon.
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– 10 – IEC 62396-2:2017 © IEC 2017

Electronic components are constantly changing. In some cases, electronic components which

had been tested become obsolete and are replaced by new electronic components which

have not been tested. The fact that an electronic component is made by the same vendor and

is of the same type as the one it replaced does not mean that the SEE data measured in the

first electronic component applies directly to the newer electronic component. In some cases,

small changes in the electronic component design or manufacturing process can have a large

effect in altering its SEE response. In addition, electronic component manufacturers typically

follow JESD46 [1] for product change notices (PCNs) to inform customers of component

design changes. JESD46 [1] recommends a part number change when a die shrink or die

foundry or die process change occurs but not when the die metallisation layout is altered,

which can also lead to different SEE results. All SEE test data published therefore should

refer to the specific manufacturer, the specific die geometry and full component part number.

5.2.2 Heavy ion data

An important resource that can be utilized to eliminate electronic components are the results

from heavy ion SEE testing carried out to support space programs (~80 % of the electronic

components tested for space applications are tested only with heavy ions). This heavy ion

SEE data can be used to calculate SEE data from high energy neutrons and protons by

utilizing a number of different calculation methods, but this requires the active involvement of

a radiation effects expert in the process. Heavy ion testing is characterized by the LET (linear

energy transfer) of the ions to which the ICs are exposed. The LET is the energy that can be

deposited per unit path length, divided by the density (units of MeV·cm /mg). With neutron

SEE, secondary particles or recoils created by the neutron interactions act as heavy ions, and

the highest possible LET of neutron-induced recoils in silicon is ~15 MeV·cm /mg [1, 2]. Thus,

any electronic component tested with heavy ions that has a LET threshold > 15 MeV·cm /mg

will be immune from neutron-induced SEE. In a recent paper summarizing SEE testing at

NASA-GSFC [3], twenty-one ICs of various types were tested with only heavy ions and eight

of them (~40 %) had LET thresholds > 15 MeV·cm /mg for diverse SEE effects.

However, for the rare commercial SRAMs that are susceptible to SEL from heavy ions [4], this

susceptibility can be increased due to the presence of small amounts of high Z materials

within the IC, for example tungsten plugs, because higher Z recoils are created which can

cause SEE reactions due to their higher values of LET. The high Z materials also lead to

higher proton and neutron SEL cross-sections due to the neutron/proton reactions producing

these recoils with higher LET and energy. Therefore heavy ion SEL cross-sections need to be

examined carefully for applicability to proton-neutron SEL susceptibility caused by embedded

high Z materials in the SRAMs. A suggested conservative value of LET threshold above which

an electronic component can be considered immune from SEL induced by neutrons is

40 MeV·cm /mg [4]. However, this caution does not apply to the primary rationale given

above for eliminating some electronic components from consideration for neutron SEE

sensitivity based on heavy ion SEE testing, since only some electronic components

incorporate these higher Z materials and the limitation applies to SEL.
Heavy ion SEE data should not be used for application to the atmospheric neutron

environment for calculation of neutron cross-section, except by scientists and engineers who

have extensive experience in using this kind of data. Unless otherwise stated explicitly, when

SEE data is discussed in the remainder of this document, it refers only to single event testing

using a neutron or proton source, not to the results from testing with heavy ions.

NOTE IEC 62396-1:2016, B.3.2, provides an approach to transforming heavy ions data into proton/neutron SEE

cross-sections.
5.2.3 High energy neutron and proton data

If SEE data on an electronic component of interest is found from SEE tests using high energy

neutrons (for example ground level testing as per JESD89A [10]) or protons, it will still require

expertise regarding how the data is to be utilized in order to calculate a SEE rate at aircraft

___________
Numbers in square brackets refer to the Bibliography.
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IEC 62396-2:2017 © IEC 2017 – 11 –

altitudes. Data obtained by electronic component vendors for their standard application to

ground level systems is often expressed in totally different units, FIT units, where one FIT is

one error in 10 electronic components hours, which is taken to apply at ground level.

5.2.4 Thermal neutron data

There is little data on thermal neutron cross-section. However a number of the spallation

neutron sources including TRIUMF, TSL and ISIS (Vesuvio) contain a substantial percentage

of thermal neutrons within the high energy beam. Using thermal neutron filters or time of flight

it is possible at such sources to determine thermal neutron cross-section. In addition there are

a number of dedicated thermal neutron sources and these are listed in IEC 62396-1.

A continuing problem with the existing SEE data is that there is no single database that

contains all of the neutron or proton SEE data. Instead, portions of this kind of SEE data can

be found published in many diverse sources. The SEE data in the larger databases is mainly

on much older electronic components, dating from the 1990s and even 1980s, and is primarily

from heavy ion tests that were performed for space applications and not from testing with

protons and neutrons.
5.3 Deciding to perform dedicated SEE tests

If existing SEE data is not available, for any one of the many reasons discussed above and

which will be further expanded upon below, then one should refer to IEC 62396-1 for the other

alternatives; in case there is no real alternative, SEE testing can be considered. The

advantage of such a test is that it pertains to the specific electronic component or board that

is of interest, but the disadvantage is that it entails making a number of important decisions

on how the testing is to be carried out. These pertain to selecting the most useful test article

(single chip or entire board), the nature of the test (static or dynamic (mainly applicable to

board testing)), assembling a test team, choosing the facility that provides the best source of

neutrons or protons for testing, scheduling and performing the test, coping with uncertainties

that appear during the test and, finally, using the test results to calculate the desired SEE rate

for avionics. Many of these issues will be discussed in Clauses 6 and 7.
6 Availability of existing SEE data for avionics applications
6.1 Variability of SEE data

Because of the diverse ways that SEE testing is carried out, and the multitude of venues for

how and where su
...