IEC TR 62240-1:2018

IEC TR 62240-1 ®
Edition 2.0 2018-03
TECHNICAL
REPORT
colour
inside
Process management for avionics – Electronic components capability in
operation –
Part 1: Temperature uprating
IEC TR 62240-1:2018-03(en)
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IEC TR 62240-1 ®
Edition 2.0 2018-03
TECHNICAL
REPORT
colour
inside
Process management for avionics – Electronic components capability in

operation –
Part 1: Temperature uprating
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 03.100.50; 31.020; 49.060 ISBN 978-2-8322-5364-9

– 2 – IEC TR 62240-1:2018 © IEC 2018
CONTENTS
FOREWORD . 5
INTRODUCTION . 7
1 Scope . 8
2 Normative references . 8
3 Terms, definitions and abbreviated terms . 8
3.1 Terms and definitions . 8
3.2 Abbreviated terms . 12
4 Selection provisions . 12
4.1 General . 12
4.2 Device selection, usage and alternatives . 14
4.2.1 General . 14
4.2.2 Alternatives . 14
4.2.3 Device technology . 14
4.2.4 Compliance with the electronic component management plan . 15
4.3 Device capability assessment . 15
4.3.1 General . 15
4.3.2 Device package and internal construction capability assessment . 15
4.3.3 Risk assessment (assembly level) . 15
4.3.4 Device uprating methods . 16
4.3.5 Device reliability assurance . 17
4.4 Device quality assurance (QA) over wider temperature ranges. 18
4.4.1 Decision for the optimum QA method . 18
4.4.2 Device level testing . 19
4.4.3 Higher level assembly testing . 19
4.5 QA process . 19
4.5.1 General . 19
4.5.2 Semiconductor device change monitoring . 19
4.5.3 Failure data collection and analysis . 19
4.6 Final electronic equipment assurance . 20
4.7 Documentation and identification . 20
4.7.1 Documentation . 20
4.7.2 Device identification . 20
4.7.3 Customer notification . 20
Annex A (informative) Device parameter re-characterisation . 22
A.1 Glossary of symbols . 22
A.2 Rationale for parameter re-characterisation . 23
A.2.1 General . 23
A.2.2 Assessment for uprateability . 23
A.3 Capability assurance . 24
A.3.1 Description . 24
A.3.2 Parameter re-characterisation process . 24
A.3.3 Application capability assessment . 29
A.4 Quality assurance . 30
A.5 Factors to be considered in parameter re-characterisation . 30
A.6 Report form for documenting device parameter re-characterisation . 32
Annex B (informative) Stress balancing. 34

B.1 General . 34
B.2 Glossary of symbols . 34
B.3 Stress balancing . 34
B.3.1 General . 34
B.3.2 Determine the ambient temperature extremes . 35
B.3.3 Determine parameter relationship to power dissipation . 35
B.3.4 Determine the dissipated power versus ambient temperature
relationship . 35
B.3.5 Assess applicability of the method . 37
B.3.6 Determine the new parameter values . 37
B.3.7 Conduct parametric and functional tests . 38
B.4 Application example . 38
B.4.1 General . 38
B.4.2 Determine the ambient temperature extremes . 39
B.4.3 Select the parameters that can be derated. 39
B.4.4 Construct an Iso-T plot . 40
J
B.4.5 Determine whether or not the device can be uprated . 40
B.4.6 Determine the new parameter values . 40
B.4.7 Conduct parametric and functional tests . 41
B.5 Other notes . 41
B.5.1 Margins . 41
B.5.2 Cautions and limitations. 41
Annex C (informative) Parameter conformance assessment . 44
C.1 General . 44
C.2 Test plan . 44
C.2.1 General . 44
C.2.2 Critical parameters . 44
C.2.3 Minimum allowable test margins . 44
C.2.4 Test options . 45
C.2.5 Quality assurance . 48
Annex D (informative) Higher assembly level testing . 51
D.1 General . 51
D.2 Process . 51
D.2.1 General . 51
D.2.2 Analysis of assembly test definition . 51
D.2.3 Perform assembly test . 51
D.2.4 Document results . 52
D.2.5 Maintenance notification . 52
Bibliography . 54

Figure 1 – Flow chart for semiconductor devices over wider temperature ranges . 13
Figure 2 – Report form for documenting device usage over wider temperature ranges . 21
Figure A.1 – Parameter re-characterisation . 23
Figure A.2 – Flow diagram of parameter re-characterisation capability assurance
process . 25
Figure A.3 – Margin in electrical parameter measurement based on the results of the
sample test . 28
Figure A.4 – Schematic diagram of parameter limit modifications . 29

– 4 – IEC TR 62240-1:2018 © IEC 2018
Figure A.5 – Parameter re-characterisation device quality assurance . 30
Figure A.6 – Schematic of outlier products that can invalidate sample testing . 31
Figure A.7 – Example of intermediate peak of an electrical parameter: Voltage
feedback input threshold change for Motorola MC34261 power factor controller, see [4] . 32
Figure A.8 – Report form for documenting device parameter re-characterisation . 33
Figure B.1 – Iso-T curve: Relationship between ambient temperature and dissipated
J
power . 36
Figure B.2 – Graph of electrical parameters versus dissipated power. 38
Figure B.3 – Iso-T curve for the Fairchild MM74HC244 . 40
J
Figure B.4 – Power versus frequency curve for the Fairchild MM74HC244 . 41
Figure B.5 – Flow chart for stress balancing . 42
Figure B.6 – Report form for documenting stress balancing . 43
Figure C.1 – Relationship of temperature ratings, requirements and margins . 45
Figure C.2 – Typical fallout distribution versus T . 47
req-max
Figure C.3 – Parameter conformance assessment flow . 49
Figure C.4 – Report form for documenting parameter conformance testing . 50
Figure D.1 – Flow chart of higher level assembly testing . 52
Figure D.2 – Report form for documenting higher level assembly test at temperature
extremes . 53

Table A.1 – Example of sample size calculation . 26
Table A.2 – Parameter re-characterisation example: SN74ALS244 octal buffer/driver . 29

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
PROCESS MANAGEMENT FOR AVIONICS – ELECTRONIC
COMPONENTS CAPABILITY IN OPERATION –

Part 1: Temperature uprating
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
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5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
The main task of IEC technical committees is to prepare International Standards. However, a
technical committee may propose the publication of a technical report when it has collected
data of a different kind from that which is normally published as an International Standard, for
example "state of the art".
IEC TR 62240-1, which is a Technical Report, has been prepared by IEC technical committee
107: Process management for avionics.
This second edition cancels and replaces the first edition published in 2013. This edition
constitutes a technical revision. This edition includes the following significant technical
changes with respect to the previous edition:
a) Revised the wording in 4.1 and the corresponding Figure 1 to reflect current industry
practices.
– 6 – IEC TR 62240-1:2018 © IEC 2018
The text of this Technical Report is based on the following documents:
CDTR Report on voting
107/313/DTR 107/322/RVDTR
Full information on the voting for the approval of this Technical Report 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 62240 series, published under the general title Process
management for avionics – Electronic components capability in operation, 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.
A bilingual version of this publication may be issued at a later date.
IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct
understanding of its contents. Users should therefore print this document using a
colour printer.
INTRODUCTION
Traditionally, industries that produced electronic equipment for ADHP (aerospace, defence
and high performance) applications have relied on the military specification system for
semiconductor device standards and upon manufacturers of military-specified devices as
device sources. This assured the availability of semiconductor devices specified to operate
over the temperature ranges required for electronic equipment in ADHP applications. In the
past, several device manufacturers have exited the military market, resulting in the decreased
availability of devices specified to operate over wide temperature ranges. Following are some
typical ambient temperature ranges at which devices are marketed:
Military:
–55 °C to + 125 °C
Automotive:
–40 °C to + 125 °C
Industrial:
–40 °C to + 85 °C
Commercial:
0 °C to + 70 °C
If there are no reasonable or practical alternatives, then a potential response is for electronic
equipment manufacturers to use devices at temperature ranges that are wider than those
specified by the device manufacturer.
This document provides information on selecting semiconductor devices, assessing their
capability to operate, and assuring their intended quality in the wider temperature ranges. It
also reports the need for documentation of such usage.
This can be supported by exchanging technical information with the original device
manufacturer.
Operation of the device beyond the manufacturer’s limits can result normally in loss of
warranty by the device manufacturer.

– 8 – IEC TR 62240-1:2018 © IEC 2018
PROCESS MANAGEMENT FOR AVIONICS – ELECTRONIC
COMPONENTS CAPABILITY IN OPERATION –

Part 1: Temperature uprating
1 Scope
This part of IEC 62240, which is a technical report, provides information when using
semiconductor devices in wider temperature ranges than those specified by the device
manufacturer. The uprating solutions described herein are considered exceptions, when no
reasonable alternatives are available; otherwise devices are utilized within the manufacturers’
specifications.
The terms “uprating” and “thermal uprating” are being used increasingly in avionics industry
discussions and meetings, and clear definitions are included in Clause 3. They were coined
as shorthand references to a special case of methods commonly used in selecting electronic
components for circuit design.
This document describes the methods and processes for implementing this special case of
thermal uprating. All of the elements of these methods and processes employ existing,
commonly used best engineering practices. No new or unique engineering knowledge is
needed to follow these processes, only a rigorous application of the overall approach.
Even though the device is used at wider temperatures, the wider temperatures usage will be
limited to those that do not compromise applications performance and reliability, particularly
for devices with narrow feature size geometries (for example, 90 nm and less). This document
does not imply that applications use the device to function beyond the absolute maximum
rating limits specified by the original device manufacturer and assumes that:
– device usage outside the original device manufacturers’ specified temperature ranges is
done only when no reasonable alternative approach is available and is performed with
appropriate justification;
– if it is necessary to use devices outside the original device manufacturers’ specified
temperature ranges, it is done with documented and controlled processes that assure
integrity of the electronic equipment.
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 TS 62239-1, Process management for avionics – Management plan – Part 1: Preparation
and maintenance of an electronic components management plan
3 Terms, definitions and abbreviated terms
3.1 Terms and definitions
For the purposes of this document, the following terms and definitions 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
3.1.1
absolute maximum ratings
limiting values of operating and environmental conditions applicable to any semiconductor
device of a specific type as defined by its published specification data, which should not be
exceeded under the worst possible conditions
[SOURCE: IEC 60134:1961, Clause 4]
3.1.2
ambient temperature
temperature of the environment in which a semiconductor device is operating
3.1.3
case temperature
temperature of the surface of a semiconductor device package during operation
3.1.4
circuit element functional mode analysis
documented analysis that determines minimum ranges and maximums of all functional
characteristics of the assembly with respect to the related functional parameters of devices
being uprated
3.1.5
COTS product
commercial off-the-shelf product
one or more components, assembled and developed for multiple commercial consumers,
whose design and/or configuration is controlled by the manufacturer’s specification or industry
standard
Note 1 to entry: COTS products can include electronic components, subassemblies or assemblies, or top level
assemblies. Electronic COTS subassemblies or assemblies include circuit card assemblies, power supplies, hard
drives, and memory modules. Top-level COTS assemblies include a fully integrated rack of equipment such as raid
arrays, file servers to individual switches, routers, personal computers, or similar equipment.
[SOURCE: IEC TS 62668-1:2016, 3.1.3]
3.1.6
device capability assessment
process of demonstrating that the device design is capable of providing the specified
functionality and operation over the wider temperature range, for the required length of time
Note 1 to entry: It assumes that the device has been qualified to operate within its specified temperature range,
and includes additional testing or analysis to evaluate expected performance at the wider temperature range.
Device capability assessment includes both performance and application-specific reliability.
3.1.7
device quality assurance over the wider temperature range
additional testing or analysis required to assure that each individual device is capable of
operating successfully in the required wider temperature range
3.1.8
device
component
material element or assembly of such elements intended to perform a required function

– 10 – IEC TR 62240-1:2018 © IEC 2018
Note 1 to entry: A device may form part of a larger device.
[SOURCE: IEC 60050-151:2001, 151-11-20, modified – The term "component" has been
added as a synonym to "device".]
3.1.8.1
semiconductor device
electrical or electronic device that is not subject to disassembly without destruction or
impairment of design use
Note 1 to entry: It is sometimes called electronic part or electronic piece part or component or electronic
component. Examples are diodes, integrated circuits, and transistors.
3.1.9
electronic equipment
any item, for example end item, sub-assembly, line-replaceable unit, shop-replaceable unit, or
system produced by an electronic equipment manufacturer
3.1.10
environmental stress screening
ESS
highly accelerated stress screening
HASS
set of production process tasks consisting in applying to the equipment concerned, within the
limits permitted by its design, particular environmental stresses in order – during
manufacturing – to reveal and eliminate the largest possible number of extrinsic defects which,

in all probability, would have appeared once utilisation had begun (early life failures)
[Source: IEC TS 62500:2008, 2.8, modified – The second term, HASS, has been added.]
3.1.11
highly accelerated test
HAT
highly accelerated life test
HALT
test during which the product or some of its component parts are subjected to environmental
and/or operating stresses that are increased progressively to values far in excess of the
specified values, up to the operating and/or destruction limits of the product
NOTE The rise in exposure time or number of cycles, whether or not associated with a combination of certain
stresses raised to values close to or equal to the specification (or stresses whose nature is not specified) may meet
the same targets as those of the highly accelerated tests, as defined in this document.
[Source: IEC TS 62500:2008, 2.10, modified – The second term, HALT, has been added and
in the note "technical specification" has been replaced by "document".]
3.1.12
junction temperature
temperature of the active region of the device in which the major part of the heat is generated
[SOURCE: SEMATECH Dictionary of Semiconductor Terms:2012]
3.1.13
manufacturer-specified parameter limits
electrical parameter limits that are guaranteed by the device manufacturer when a device is
used within the recommended operating conditions
3.1.14
manufacturer-specified temperature range
operating temperature range over which the component specifications, based on the
component data sheet, are guaranteed by the electronic component manufacturer

Note 1 to entry: Manufacturer-specified temperature range is a subset of the recommended operating conditions.
3.1.15
parameter conformance assessment
process for thermal uprating in which devices are tested to assess their conformance to the
manufacturer-specified parameter limits over the target wider temperature range
3.1.16
parameter temperature characterisation
process of determining the specification values of electrical parameters by testing samples
over the manufacturer’s specified temperature range
3.1.17
parameter temperature re-characterisation
process for thermal uprating in which the device parameters are re-defined as a result of
testing performed
3.1.18
PCB assembly uprating
CCA uprating
uprating of a printed circuit board or circuit card assembly populated with individual
components, some or all of which are operated at temperatures beyond their data sheet
parameters
3.1.19
rating
value that establishes either a limiting capability or a limiting condition for a semiconductor
device
3.1.20
recommended operating conditions
conditions for use of the component for which the component specifications, based on the
component data sheet, are identified by the electronic component manufacturer
3.1.21
stress balancing
process for thermal uprating in which at least one of the device’s electrical parameters is kept
below its maximum allowable limit to reduce heat generation, thereby allowing operation at a
higher ambient temperature than that specified by the device manufacturer
3.1.22
target temperature range
operating temperature range of the device in its required application
3.1.23
thermal uprating
uprating
process to assess the capability of a part to meet the performance requirements of the
application in which the device is used outside the manufacturer’s specified temperature
range
Note 1 to entry: Terms such as “upscreening”, “retest”, “up-temperature testing” and other similar variations are
subsets of or encompassed by the overall uprating process.
3.1.24
wider temperature range
target temperature range outside the manufacturer-specified temperature range

– 12 – IEC TR 62240-1:2018 © IEC 2018
Note 1 to entry: It may include temperatures that are higher or lower than the manufacturer-specified temperature
range, or both.
3.2 Abbreviated terms
ADHP aerospace, defence and high performance
AQEC aerospace qualified electronic component
ATP acceptance test procedure
CAGE commercial and government entity
CCA circuit card assembly
COTS commerical off-the-shelf
CMOS complementary metal-oxide-semiconductor
ECMP electronic components management plan
ESD electro-static discharge
ESS environmental stress screening
HALT highly accelerated life testing
HAT highly accelerated test
HASS highly accelerated stress screening
ID Identification
PCB printed circuit board
PCN process change notice
PPM parts per million
SD sigma deviation
QA quality assurance
4 Selection provisions
4.1 General
Selection provisions are described below.
The flow chart of Figure 1 describes a typical approach for using devices outside the
electronic component manufacturer’s specified temperature range, by considering their
selection (4.2), their capability assessment (4.3), their quality assurance (4.4 and 4.5) and
their documentation (4.7).
The use of devices that operate outside the temperature ranges specified by the device
manufacturer is discouraged; however, such usage can occur if other options prove to be
impossible, unreasonable, or impractical. Justification for such usage can be based on
availability, functionality, or other relevant criteria.
Such operation is not cause for unstable part operation or loss of electronic equipment
function nor is the device to be operated beyond its absolute maximum data sheet ranges (for
example maximum junction temperature).
The electronic equipment manufacturer uprating the component utilizes a process to
demonstrate that the component will meet reliability and lifetime requirements of the ADHP
application.
Additionally, operation of the device beyond the electronic component manufacturer’s limits
can result normally in loss of warranty by the device manufacturer.
NOTE The headings of Clause 4 are keyed to the actions and decisions of Figure 1.

Figure 1 – Flow chart for semiconductor devices over wider temperature ranges

– 14 – IEC TR 62240-1:2018 © IEC 2018
4.2 Device selection, usage and alternatives
4.2.1 General
The electronic equipment is designed and devices are selected so that, initially and
throughout electronic equipment life, no absolute maximum value for the intended service is
exceeded for any device under the worst probable operating conditions.
Operating condition examples include the following: supply voltage variation, electronic
equipment device variation, electronic equipment control adjustment, load variations, signal
variation, environmental conditions, and variation in characteristics of the device under
consideration and of all other electronic devices in the electronic equipment.
4.2.2 Alternatives
A review of alternatives is to be performed prior to using a device outside the manufacturer’s
specified temperature range. If an alternative can be shown to be reasonable and practical,
then it is selected. The results of this evaluation are then documented.
Examples of potential alternatives include:
– using a device specified over the required temperature range, with identical function, but
from a different manufacturer;
– using a device specified over the required temperature range, with identical function, but a
wider specified temperature range. Examples include: AQEC (aerospace qualified
electronic components according to IEC TS 62564-1), automotive grade specified devices,
or other extended range specified devices;
– using a device specified over the required temperature range, with identical function, but a
different package;
– using a device specified over the required temperature range, that has slightly different
specified parameter limits, but which still meets the electronic equipment design goals;
– using a device with identical function, but a specified temperature range that still meets
the application requirement;
– using a device specified over the required temperature range, but with a different function,
and compensating by making changes elsewhere in the electronic equipment design;
– modifying the device’s local operating environment, for example, adding cooling, etc.;
– modifying the electronic equipment's specified ambient temperature requirement, in co-
operation with the customer;
– modifying the electronic equipment's operating or maintenance procedures, in co-
operation with the customer; and
– negotiating with the device manufacturer to provide assurance over the wider temperature
range.
For most applications, the preferred device for use in a wider temperature range is the one for
which the extension beyond the specified range is the least, i.e., upon making the decision to
uprate a given manufacturer’s part and if the manufacturer offers the device in various
temperature ranges, then the widest temperature range is selected. For example, given the
choice to uprate a manufacturer part available in a commercial temperature range (0 °C to
70 °C) versus the same device available in industrial grade (–40 °C to 85 °C) or automotive
grade (–40 °C to 125 °C), then the device having the widest range is selected.
4.2.3 Device technology
The technology of a device and its package are to be identified and understood in sufficient
detail to assess the likelihood and consequences of potential failure mechanisms. If available,
manufacturer data, information and/or guidance are collected at the onset.

4.2.4 Compliance with the electronic component management plan
All devices considered for use in wider temperature ranges are to be compliant with the
electronic equipment manufacturer’s ECMP.
NOTE IEC TS 62239-1 is a resource for an ECMP.
4.3 Device capability assessment
4.3.1 General
The assessment of device capability needs to assure that not only are device parameters
acceptable, but also that device functionality and functionality of the related circuit application
are acceptable as well. Therefore, functional testing at the application or higher levels is
recommended.
4.3.2 Device package and internal construction capability assessment
Device qualification test data and other applicable data when available are to be analysed to
assure that:
a) they support the operation of the device over the end use temperature range and that the
package and internal construction type used in device qualification is the same as that to
be used in the end application;
b) the package and internal construction can withstand the stresses resulting from wider
temperature cycling ranges, and that the package materials do not undergo deleterious
phase changes or changes in material properties in the wider temperatures.
If data are not available, then relevant testing based on the application is to be considered.
4.3.3 Risk assessment (assembly level)
A preliminary risk assessment is to be performed to help guide decisions regarding the
method(s) of capability assessment and quality assurance (QA) to be used, as well as how
and when they are applied. Understanding the risks on an application-specific basis enables
“risk informed” decision-making and thereby a prediction of the impact of critical decisions.
The process for assessing risks considers applicable factors associated with the use of
devices beyond the manufacturer’s specified temperature range. Risk factors in this
assessment may include:
– application criticality into which the device will be used;
– consequences of failure at device, circuit assembly and system level;
– type or technology of the device under consideration;
– manufacturer data available for the device;
– quality/reliability monitors employed by the manufacturer including lot-to-lot variation;
– comprehensiveness of production assembly-level screens performed at extended
temperature;
– identification of both managed and unmanaged risks.
Details about the likelihood of occurrence, consequences of occurrence, and acceptable
mitigation approaches for each identified risk are generated. Each risk normally falls into one
of the following categories:
• functionality risks: risks for which the consequences of occurrence are loss of electronic
equipment, loss of mission, or unacceptable performance. Functionality risks impair the
product’s capability to operate to the customer’s specification;
• “produceability” risks: risks for which the consequences of occurrence are schedule
impacts. “Produceability” risks determine the probability of successfully

– 16 – IEC TR 62240-1:2018 © IEC 2018
manufacturing/fabricating the product (where “successfully” refers to some combination of
schedule, manufacturing yield, quantity and other factors).
Several approaches are possible, and each approach constitutes a unique mixture of risk
mitigation factors. The results of a preliminary risk assessment should provide insight and
assistance to the selection of a viable approach or approaches for establishing the capability
of devices being used outside the manufacturer’s specified temperature range.
NOTE Uprating can be supported by exchanging technical information with the original device manufacturer.
4.3.4 Device uprating methods
4.3.4.1 General
Devices are to be reviewed to determine the optimum method of uprating based on risk
assessment. Options include:
a) device parameter re-characterisation, see 4.3.4.2;
b) device stress balancing, see 4.3.4.3;
c) device parameter conformance assessment, see 4.3.4.4;
d) higher assembly level testing, see 4.3.4.5.
Where possible, devices for uprating are taken from a single lot. The use of additional lots (or
samples) may be utilized to undergo testing as part of the initial char
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