IEC TR 62240:2005

TECHNICAL IEC
REPORT TR 62240
First edition
2005-06
Process management for avionics –
Use of semiconductor devices
outside manufacturers' specified
temperature range
Reference number
IEC/TR 62240:2005(E)
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TECHNICAL IEC
REPORT TR 62240
First edition
2005-06
Process management for avionics –
Use of semiconductor devices
outside manufacturers' specified
temperature range
 IEC 2005  Copyright - all rights reserved
No part of this publication may be reproduced or utilized in any form or by any means, electronic or
mechanical, including photocopying and microfilm, without permission in writing from the publisher.
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– 2 – TR 62240  IEC:2005(E)
CONTENTS
FOREWORD.4
INTRODUCTION.6

1 Scope.7
2 Normative references .7
3 Terms and definitions .7
4 Objectives .10
5 Using devices outside the manufacturer's specified temperature ranges.10
5.1 Device selection, usage and alternatives.10
5.2 Device capability assessment.12
5.3 Device quality assurance in wider temperature ranges .15
5.4 Documentation .16
5.5 Device identification .16

Annex A (informative) Device parameter re-characterisation .19
A.1 Glossary of Symbols.19
A.2 Rationale for parameter re-characterisation .20
A.3 Capability assurance .21
A.4 Quality assurance.28
A.5 Factors to be considered in parameter re-characterisation.28
A.6 References .30

Annex B (informative) Stress balancing .32
B.1 General .32
B.2 Glossary of symbols.32
B.3 Stress balancing.33
B.4 Application example.36
B.5 Other notes.39

Annex C (informative) Parameter conformance assessment.42
C.1 General .42
C.2 Test plan.42

Annex D (informative) Higher assembly level testing.49
D.1 General .49
D.2 Process.49

Bibliography.52

TR 62240  IEC:2005(E) – 3 –
Figure 1 – Flow chart for semiconductor devices in wider temperature ranges .17
Figure 2 – Report form for documenting device usage in wider temperature ranges .18
Figure A.1 – Parameter re-characterisation.20
Figure A.2 – Flow diagram of parameter re-characterisation capability assurance
process.23
Figure A.3 – Margin in electrical parameter measurement based on the results of
sample test .26
Figure A.4 – Schematic diagram of parameter limit modifications.27
Figure A.5 – Parameter Re-Characterisation Part Quality Assurance .28
Figure A.6 – Schematic of outlier products that may invalidate sample testing .29
Figure A.7 – Example of intermediate peak of an electrical parameter: voltage
feedback input threshold change for Motorola MC34261 power factor controller [4] .30
Figure A.8 – Report form for documenting device parameter re-characterisation.31
Figure B.1 – Iso-T curve: the relationship between ambient temperature and
J
dissipated power.34
Figure B.2 – Graph of electrical parameters versus dissipated power .35
Figure B.3 – Iso-TJ curve for the Fairchild MM74HC244 .38
Figure B.4 – Power versus frequency curve for the Fairchild MM74HC244.39
Figure B.5 – Flow chart for stress balancing .40
Figure B.6 – Report form for documenting stress balancing .41
Figure C.1 – Relationship of temperature ratings, requirements and margins.43
Figure C.2 – Typical Fallout Distribution versus T .45
req-max
Figure C.3 – Parameter conformance assessment flow.47
Figure C.4 – Report form for documenting parameter conformance testing .48
Figure D.1 – Flow chart of higher level assembly testing.50
Figure D.2 – Report form for documenting higher level assembly test at temperature
extremes.51

Table A.1 – Example of sample size calculation.24
Table A.2 – Parameter re-characterisation example: SN74ALS244 Octal Buffer/Driver .27

– 4 – TR 62240  IEC:2005(E)
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
PROCESS MANAGEMENT FOR AVIONICS –
USE OF SEMICONDUCTOR DEVICES OUTSIDE
MANUFACTURERS' SPECIFIED TEMPERATURE RANGE

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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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 62240, which is a technical report, has been prepared by IEC Technical Committee 107:
Process management for avionics.
This Technical Report cancels and replaces IEC/PAS 62240 published in 2001. This first
edition constitutes a technical revision.

TR 62240  IEC:2005(E) – 5 –
The text of this technical report is based on the following documents:
Enquiry draft Report on voting
107/33/DTR 107/36/RVC
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 publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
The committee has decided that the contents of this publication will remain unchanged until
the maintenance result date indicated on the IEC web site under "http://webstore.iec.ch" in
the data related to the specific publication. At this date, the publication will be
• reconfirmed;
• withdrawn;
• replaced by a revised edition, or
• amended.
A bilingual version of this publication may be issued at a later date.

– 6 – TR 62240  IEC:2005(E)
INTRODUCTION
Traditionally, industries that produce electronic equipment for rugged 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 rugged applications. Many device manufacturers have exited the
military market in recent years, resulting in 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 equipment
manufacturers to use devices in temperature ranges that are wider than those specified by the
device manufacturer. This practice, properly documented and controlled, is used by electronic
equipment manufacturers to meet the design goals of their equipment.
This technical report gives practices and procedures to select semiconductor devices; to
assess their capability to operate; and to assure their intended quality in the wider
temperature ranges. It also reports the documentation of such usage.

TR 62240  IEC:2005(E) – 7 –
PROCESS MANAGEMENT FOR AVIONICS –
USE OF SEMICONDUCTOR DEVICES OUTSIDE
MANUFACTURERS' SPECIFIED TEMPERATURE RANGE

1 Scope
This technical report reports processes that exist for using semiconductor devices in wider
temperature ranges than those specified by the device manufacturer.
This technical report reports on applications in which only the performance of the device is an
issue. Even though the device is used at wider temperatures, the wider temperatures will be
limited to those that do not compromise the system performance or application-specific
reliability of the device in the application. Specifically, this technical report does not report on
applications that require the device to function beyond the absolute maximum rating limits of
the component specified by the manufacturer and with a margin to be considered.
NOTE Alternate means of thermal uprating may have been performed prior to the implementation reported in this
technical report by the equipment manufacturer. Rationale for decisions made may have been valid considering the
application, semiconductor market conditions, experience with the particular component manufacturer, etc. at the
times these decisions were made. Field performance using these methods also may validate their use, however,
their continued use should take into account the risk of changes to the subject devices such as feature size
reductions, material changes, etc.
2 Normative references
The following referenced documents are indispensable for the application of this technical
report. For dated references, only the edition cited applies. For undated references, the latest
edition of the referenced document (including any amendments) applies.
IEC 62239, Process management for avionics – Preparation of an electronic components
management plan
3 Terms and definitions
For the purposes of this technical report, the following terms and definitions are used herein
and/or should be used when using devices outside the manufacturers' specified temperature
ranges.
NOTE The terms uprating and thermal uprating are being used increasingly in avionics industry discussions and
meetings, and clear definitions are included in this clause. They were coined as shorthand references to a special
case of methods commonly used in selecting components for circuit design. This technical report describes the
methods and processes for implementing this special case. All of the elements of these processes employ existing,
commonly used engineering practices. No new or unique engineering knowledge is required to follow these
processes: only a rigorous application of the overall approach.
3.1
absolute maximum ratings
limiting values of operating and environmental conditions applicable to any semiconductor
device of a specific type as defined by its published data, which should not be exceeded
under the worst possible conditions. These values are chosen by the device manufacturer to
provide acceptable serviceability of the device, taking no responsibility for equipment
variations, and the effects of changes in operating conditions due to variations in the
characteristics of the device under consideration and all other electronic devices in the
equipment
[IEC 60134:1961, Clause 4, modified]

– 8 – TR 62240  IEC:2005(E)
3.2
ambient temperature
temperature of the environment in which a semiconductor device is operating
3.3
case temperature
temperature of the surface of a semiconductor device package during operation
3.4
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
3.5
device capability assessment
process of demonstrating that the device design is capable of providing the specified
functionality, over the wider temperature range, for the required length of time. 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
3.6
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
3.7
ECMP
Electronic Components Management Plan
3.8
semiconductor devices
electronic devices that are not subject to disassembly without destruction or impairment of
design use. They are sometimes called electronic parts or piece parts. Examples are diodes,
integrated circuits, and transistors
3.9
electronic equipment
any item, for example, end item, sub-assembly, line-replaceable unit, shop-replaceable unit,
or system produced by an electronic equipment manufacturer
3.10
junction temperature
temperature of the active region of the device in which the major part of the heat is generated
[International SEMATECH Official Dictionary, Rev 5.0, modified]
3.11
manufacturer-specified parameter limits
electrical parameter limits that are guaranteed by the device manufacturer when a device is
used within the recommended operating conditions (see Rating)

TR 62240  IEC:2005(E) – 9 –
3.12
manufacturer-specified temperature range
operating temperature range over which the component specifications, based on the
component data sheet, are guaranteed by the component manufacturer (see Rating)
NOTE Manufacturer-specified temperature range is a subset of the recommended operating conditions.
3.13
may
indicates a course of action which is permissible within the limits of this technical report
3.14
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 temperature range
3.15
parameter characterisation
process of determining the typical and limiting values of electrical parameters by testing
representative samples at room and extreme temperatures over the manufacturer’s specified
temperature range
3.16
parameter re-characterisation
process for thermal uprating in which the device parameters are characterised over the target
temperature range, leading to a possible re-specification of the manufacturer-specified
parameter limits
3.17
rating
value that establishes either a limiting capability or a limiting condition for a semiconductor
device
3.18
recommended operating conditions
conditions for use of the component for which the component specifications, based on the
component data sheet, are guaranteed by the component manufacturer (see Rating)
3.19
shall
indicates a mandatory requirement to be followed in order to conform to this technical report
3.20
should
indicates that, among several possibilities, one is recommended as particularly suitable,
without mentioning or excluding others; or that a certain course of action is preferred but not
necessarily required; or that (in the negative form) a certain course of action is deprecated but
not prohibited
3.21
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

– 10 – TR 62240  IEC:2005(E)
3.22
target temperature range
operating temperature range of the device in its required application
3.23
thermal 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 (see Uprating)
3.24
uprating
process to assess the capability of a device to meet the performance requirements of the
application in which the device is used outside the manufacturer’s specification range
NOTE Terms such as “upscreening”, “retest”, “up-temperature testing” and other similar variations are all deemed
to be subsets of or encompassed by the overall uprating process.
3.25
wider temperature range
target temperature range outside the manufacturer-specified temperature range. It may
include temperatures that are higher or lower than the manufacturer-specified temperature
range, or both
3.26
will
expresses a declaration of intent
4 Objectives
The objectives of this technical report are:
– to ensure that device usage outside the manufacturers’ specified temperature ranges is
done only with appropriate justification; and
– to ensure that, if it is necessary to use devices outside the manufacturers’ specified
temperature ranges, it is done with documented and controlled processes that assure the
integrity of the equipment.
5 Using devices outside the manufacturer's specified temperature ranges
Devices used outside the manufacturers specified temperature range shall be selected (5.1),
their capability assessed (5.2), and their quality assured (5.3), and documented (5.4), as
illustrated by the flow chart of Figure 1.
NOTE The headings of this clause are keyed to the actions and decisions of Figure 1.
5.1 Device selection, usage and alternatives
The equipment manufacturer shall design so that, initially and throughout life, no absolute-
maximum value for the intended service is exceeded for any device under the worst probable
operating conditions with respect to supply voltage variation, equipment device variation,
equipment control adjustment, load variations, signal variation, environmental conditions,
variation in characteristics of the device under consideration and of all other electronic
devices in the equipment.
TR 62240  IEC:2005(E) – 11 –
5.1.1 Alternatives
A review of alternatives shall be carried out 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 shall be selected. The results of the evaluation shall be documented.
Examples of potential alternatives include:
– using a device specified over the required temperature range, with the identical function,
but from a different manufacturer;
– using a device specified over the required temperature range, with the identical function,
but a wider specified temperature range;
– using a device specified over the required temperature range, with the 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 equipment design goals;
– using a device with the identical function, but a specified temperature range that still
meets the application requirement;
– using a device specified over the required temperature range, but a different function, and
compensating by making changes elsewhere in the equipment design;
– modifying the device’s local operating environment, for example, adding cooling, etc.;
– modifying the equipment specified ambient temperature requirement, in co-operation with
the customer;
– modifying the equipment 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 should be
the one for which the extension beyond the specified range is least.
NOTE As an example of this requirement, consider the case in which the required ambient temperature is 92 °C,
and no device specified to operate above 85 °C is available. If the two available devices have specified maximum
ambient temperatures of 70 °C and 85 °C, then the 85 °C device should, in the absence of other factors, be given
preference regarding temperature.
5.1.2 Device technology
The technology of a device and its package shall be identified and understood in sufficient
detail to assess the likelihood and consequences of potential failure mechanisms. It is
recommended that the device manufacturer be consulted when a device is proposed for use
outside manufacturers' specified temperature range. If the device manufacturer discourages
the uprating process arguing technical reasons, the user needs to assess the impact of those
reasons against the user’s specific application.
5.1.3 Compliance with the Electronic Component Management Plan
All devices considered for use in wider temperature ranges shall be compliant with the
equipment manufacturer’s ECMP. It is necessary for ECMP requirements to be met only for
the temperature range over which the device is specified, since requirements for wider
temperatures are provided in this technical report.
NOTE IEC 62239 is recommended as a resource for an ECMP.

– 12 – TR 62240  IEC:2005(E)
The use of devices outside the temperature ranges specified by the device manufacturer is
discouraged; however, such usage may occur if other options prove to be impossible,
unreasonable, or impractical. Justification for such usage may be based on availability,
functionality, or other relevant criteria. In no case will such usage result in a design that:
– requires the device to operate at an operating or environmental stress level that
significantly increases the risk of unstable device operation or loss of equipment function;
or
– requires the device to operate beyond the device’s maximum junction temperature or any
other limiting temperature, as specified by the device manufacturer, or calculated directly
from parameters specified by the device manufacturer.
5.2 Device capability assessment
The assessment of device capability needs to assure that not only are device parametrics
acceptable, but also that device functionality and functionality of the related circuit are
acceptable as well. Therefore, functional testing at the application or circuit level and higher
levels as well is recommended.
5.2.1 Device package and internal construction capability assessment
Device qualification test data and other applicable data when available shall be analyzed to
assure that 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.
Device qualification test data and other applicable data when available shall be analyzed to
assure that 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 this data is not available, then relevant testing based on the application should be
considered.
5.2.2 Risk assessment (assembly level)
A preliminary risk assessment is prudent at this point to help guide decisions regarding the
method(s) of capability assessment to be used, as well as how and when they should be
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 should consider applicable factors associated with the use of
devices beyond the manufacturers 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 and system level;
– type or technology of device under consideration;
– manufacturer data available for the device;
– quality/reliability monitors employed by the manufacturer;
– comprehensiveness of production assembly-level screens performed at extended
temperature;
– identification of both managed and unmanaged risks and cost models for each.

TR 62240  IEC:2005(E) – 13 –
Details about the likelihood of occurrence, consequences of occurrence, and acceptable
mitigation approaches for each identified risk should be generated. Each risk normally falls
into one of the following categories:
– functionality risks – risks for which the consequences of occurrence are loss of equipment,
loss of mission, or unacceptable performance. Functionality risks impair the product’s
capability to operate to the customer’s specification;
– producibility risks – risks for which the consequences of occurrence are financial impacts
(reduction in profitability). Producibility risks determine the probability of successfully
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.
5.2.2.1 Device parameter re-characterisation
Device parameter re-characterisation consists of characterising the device parameters over a
temperature range beyond that specified by the device manufacturer and, as a result, re-
specifying some of the data sheet parameter values or tolerances in the wider temperature
range. The device then may be used in applications in which the newly specified parameters
provide the required functionality. To effectively assess device manufacturing variability,
multiple date codes need to be considered, with the recognition that this may be application
and usage rate dependent.
If device parameter re-characterisation is chosen for capability assessment, then the process
described in Annex A shall be followed.
If device parameter re-characterisation is chosen for capability assessment, it shall be used
in conjunction with a quality assurance process that includes device testing, as described
in 5.3.1.
5.2.2.2 Device stress balancing
Device stress balancing consists of operating the device at an ambient temperature above
that specified by the device manufacturer; and compensating by reducing at least one of the
other operating parameters, for example, power, speed, to the extent that the junction
temperature remains below its maximum rating, with acceptable specified margin.
If device stress balancing is chosen for capability assessment, then the process described in
Annex B shall be followed.
5.2.2.3 Device parameter conformance assessment
If device parameter conformance is chosen for capability assessment, then the devices shall
be tested over the entire wider temperature range, according to the process described in
Annex C.
Sampling procedures and failure criteria for device testing should be according to Annex C.
Where less than 100 % are sampled, then device testing also shall include testing at a higher
level of assembly over the entire wider temperature range.

– 14 – TR 62240  IEC:2005(E)
5.2.2.4 Higher assembly level testing at temperature extremes
Higher assembly level testing at temperature extremes consists of testing the device over the
entire wider assembly ambient temperature range, while the device is incorporated into a
higher level of assembly.
If higher assembly level testing is chosen for capability assessment, then the process
described in Annex D shall be followed.
NOTE 1 A higher level of assembly may include a module, a printed circuit card, another sub-assembly, or the
end item.
NOTE 2 The intent of 5.2.2.3 and 5.2.2.4 is to ensure that, if testing is used to assess device capability, then
each device is tested at least once over its entire wider operating ambient temperature range. Higher-assembly-
level testing results are applicable only to the design revision of the assembly. For other assembly revisions,
additional testing or analysis should be performed.
The following steps shall be followed:
a) Perform a Circuit Element Functional Mode Analysis to determine the device
functions/parameters to be tested in order to assure assembly functionality across the
target ambient temperature range.
b) Review the assembly level test plan to determine its capability to test the parameters
required for successful operation in the assembly. If the test plan is not capable, and
cannot be modified to be capable, than this method of uprating is rejected for the
application.
c) Conduct the test, analyze the results, and document the conclusions.
d) Insert instructions in the maintenance procedures to require full acceptance test over the
target ambient temperature range. This testing applies after every maintenance action
that involves replacement of an electronic device at the assembly level for which the
original capability assessment was performed, unless the maintenance manual provides
adequate alternate procedures. This test should be conducted at an assembly level at
which the original capability assessment was done, or higher.
5.2.3 Device reliability assurance
Device manufacturers generally qualify devices (including reliability assessment) using the
same processes, regardless of the temperature ranges for which they are specified. Generally,
they do not represent their products to have a guarantee of lifetime in any application,
because they do not know what the use conditions will be. Caution should be exercised when
using past experience of the device within the manufacturers specified temperature range to
infer reliability outside of the manufacturers specified temperature range.
The application of each device and any related impacts on reliability should be assessed. New
and/or accelerated failure mechanisms, which might be evident at the wider temperature
range, should be clearly identified and their effects on reliability established. If deemed
necessary, additional testing can be implemented to address application reliability concerns.
NOTE 1 The distribution of time that a device is actually operating beyond a device manufacturer’s specified
temperature range and the related impact on reliability need to be considered. Uprating conditions often occur only
as “corner conditions” or for specified extreme environments which are seldom experienced. Device manufacturers
should be consulted to assist in the assessment of related reliability impacts for these conditions.
The following steps shall be followed:
a) Qualify the devices according the requirements of the user’s Electronic Component
Management Plan, as specified in 5.1.2 of this technical report; qualify electrical
performance of the devices over the intended range of operating and environmental
conditions after a reliability stress conditioning exposure that reflects the life cycle of the
application; and determine a margin, supported by analysis using adequate data from the
intended application, between the maximum operating junction temperature and the
absolute maximum rated junction temperature.

TR 62240  IEC:2005(E) – 15 –
b) The absolute maximum rating of the junction temperature of the device as defined in
clause 3 of this technical report, with a default margin of 20 °C should not be exceeded.
Other margins may be used if the device user has data to justify them.
NOTE 2 Device reliability can decrease as junction temperature, Tj, approaches maximum. This is a function of
time in application at that temperature. If the average Tj of the device is expected to approach maximum in the
application, the reliability impact should be addressed. Note also that many avionics applications specify a high
temperature environment in which the device is required to operate. The reliability impact on the device is not
driven by a thermal condition that is very seldom experienced.
5.3 Device quality assurance in wider temperature ranges
Regardless of the process used to assure device capability, the quality assurance processes
documented in the equipment manufacturer’s ECMP shall be applied to the device.
5.3.1 Device parameter re-characterisation testing
If device parameter re-characterisation (5.2.2.1) is used for capability assessment, then the
device quality shall be assured by testing incoming devices according to a defined sampling
plan and effective supplier change notice monitoring.
NOTE The intent of this guideline is to monitor the devices to assure that, subsequent to the capability assurance
activity, no changes are made in the design or manufacturing processes of the device that will adversely affect its
capability in the wider temperature range.
5.3.2 Device parameter conformance testing
If device parameter conformance assessment (5.2.2.3) or higher assembly level testing at
temperature extremes (5.2.2.4) is used for capability assessment, then the device quality
shall be assured through device parameter conformance testing (this section), higher level
assembly testing (5.3.3) or both, depending on the results of the risk assessment in 5.2.2.
See Figure 1 for a flow chart of this process. If this method is used for quality assurance, the
device assessment process shall be done initially by testing all individual devices before use
in production equipment or by temperature testing all production equipment at the ambient
temperature extremes.
Based on data derived from such testing, testing may be reduced or eliminated by satisfactory
test history and by effective supplier change notice monitoring. The sampling rate, confidence
limits, and decision criteria shall be as stated in Annex C.
5.3.3 Higher level assembly testing
If higher assembly level testing at temperature extremes (5.2.2.4) or device parameter
conformance assessment (5.2.2.3) is used for capability assessment, then the device quality
shall be assured through device parameter conformance testing (5.3.2), higher level
assembly testing (this subclause), or both, depending on the results of the risk assessment
in 5.2.2. See Figure 1 for flow chart showing this process. If this subclause is chosen for
quality assurance, a process similar to that outlined in Annex D shall be used to determine
the capability of the assembly test to validate the uprated device at the target temperature.
Assembly level tests are designed to test basic functional performance of an assembly or
device. Typically, all functions or “key characteristics” of the end product are typically verified
at the sub-assembly or end-item level. The difference between the typical case and the
process described here is that the device’s role in these functions, or “key characteristics”, of
the assembly are traced, and its capability verified by assembly test over the target
temperature range.
5.3.4 Change monitoring
Device data (such as product change notices or manufacturer data) shall be monitored to
give warning of device changes that may affect the capability of the device to operate over the
wider temperature range as established in 5.2.

– 16 – TR 62240  IEC:2005(E)
The requirement for monitoring component design and component manufacturing process
change data is no different than the related requirement in the IEC 62239 ECMP specification.
5.3.5 Failure data collection and analysis
Failure data should be collected for all uprated devices. When clear trends are evident, the
data should be analysed and correct
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