IEC 62483:2013

IEC 62483 ®
Edition 1.0 2013-09
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Environmental acceptance requirements for tin whisker susceptibility of tin and
tin alloy surface finishes on semiconductor devices

Exigences de réception environnementale pour la susceptibilité des finis de
surface en étain et alliage d'étain à la trichite d'étain sur les dispositifs à
semiconducteurs
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IEC 62483 ®
Edition 1.0 2013-09
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Environmental acceptance requirements for tin whisker susceptibility of tin and

tin alloy surface finishes on semiconductor devices

Exigences de réception environnementale pour la susceptibilité des finis de

surface en étain et alliage d'étain à la trichite d'étain sur les dispositifs à

semiconducteurs
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX X
ICS 31.080.01 ISBN 978-2-8322-1103-8

– 2 – 62483 © IEC:2013
CONTENTS
1 Scope . 8
2 Terms and definitions . 8
3 Test method for measuring tin whisker growth . 14
3.1 Procedure . 14
3.2 Test samples . 14
3.3 Handling precaution . 15
3.4 Reflow assembly . 15
4 Acceptance procedure for tin and tin alloy surface finishes . 16
4.1 Determination of whether a technology, manufacturing process, or similarity
acceptance test is required . 16
4.2 Samples . 22
4.2.1 Sample requirements . 22
4.2.2 Sample size for multi-leaded components with 5 or more leads . 22
4.2.3 Sample size for passive and discrete components with 4 leads or
fewer . 22
4.2.4 Additional samples . 22
4.3 Test procedures and durations . 23
4.3.1 Preconditioning . 23
4.3.2 Test conditions . 24
4.3.3 Test durations . 24
4.3.4 Whisker inspection . 24
4.3.5 Surface corrosion observed during high temperature/humidity testing . 24
4.4 Determination of the class level for testing . 27
5 Acceptance criteria . 28
5.1 General . 28
5.2 Through-hole lead termination exclusions . 28
6 Reporting of results . 29
6.1 General requirements . 29
6.2 Description of the surface finish, defined by technology and process
parameters in Table 2 . 30
6.3 Samples and preconditioning . 30
6.4 Acceptance testing . 30
7 On-going tin whisker evaluation . 30
Annex A (normative) Test method for measuring whisker growth on tin and tin alloy
surface finishes of semiconductor devices . 32
A.1 Overview . 32
A.2 Disclaimer . 32
A.3 Apparatus . 34
A.3.1 Temperature cycling chambers . 34
A.3.2 Temperature humidity chambers . 34
A.3.3 Optical stereomicroscope (optional) . 34
A.3.4 Optical microscope (optional) . 34
A.3.5 Scanning electron microscope . 34
A.3.6 Convection reflow oven (optional) . 34
A.4 Validation of optical microscopy equipment . 35
A.4.1 Overall criteria . 35
A.4.2 Capability of whisker detection . 35

62483 © IEC:2013 – 3 –
A.4.3 Capability of whisker length measurement . 36
A.4.4 Capability of whisker density measurement . 36
A.5 Sample requirements and optional preconditioning . 36
A.5.1 Acceptance requirements . 36
A.5.2 Scientific studies . 37
A.5.3 Test coupons . 37
A.5.4 Optional test sample preconditioning . 37
A.6 Whisker inspection, length measurement and test conditions . 39
A.6.1 General principles . 39
A.6.2 Handling . 39
A.6.3 General inspection instructions . 39
A.6.4 Initial pretest inspection . 40
A.6.5 Test conditions . 40
A.6.6 Screening inspection . 41
A.6.7 Detailed inspection . 41
A.6.8 Recording procedure for scientific studies . 43

Figure 1 – Cross-sectional view of component surface finishes . 8
Figure 2 – Typical photographs of termination corrosion . 10
Figure 3 – Examples of tin whiskers . 12
Figure 4 – Non-whisker surface formations . 13
Figure 5 – Whisker length measurement . 13
Figure 6 – Minimum lead-to-lead gap . 14
Figure 7 – Flowchart to determine whether a technology acceptance test, a
manufacturing process acceptance test or no testing is required on the basis of
similarity . 17
Figure 8 – Technology acceptance test flow for multi-leaded components using copper
alloy leadframe with post bake mitigation technology – Surface finish test sample,
technology parameters fixed (1 of 2) . 18
Figure A.1 – Process flow for Sn whisker testing . 33
Figure A.2 – Optional preconditioning reflow profile . 39
Figure A.3 – Examples of whiskers in areas of corrosion . 40
Figure A.4 – A schematic diagram depicting a component lead and the top, 2 sides,
and bends of the lead to be inspected . 42
Figure A.5 – A schematic drawing depicting a leadless component and the top and 3
sides of the terminations to be inspected . 42
Figure A.6 – A schematic drawing depicting one possible coupon and three 1,7 mm
areas identified for inspection . 42

b
Table 1 – SMT board assembly process guidance for minimum termination wetting . 16
Table 2 – Surface finish technology and manufacturing process change acceptance
parameters . 20
Table 3 – Tin and tin alloy surface finish acceptance test matrix . 21
Table 4 – Tin and tin alloy surface finish acceptance test sample size requirements
per precondition treatment for multi-leaded component . 23
Table 5 – Tin and tin alloy surface finish acceptance test sample size requirements per
precondition treatment for passive and discrete components with 4 leads or fewer . 23
Table 6 – Technology acceptance tests and durations . 25

– 4 – 62483 © IEC:2013
Table 7 – Manufacturing process change acceptance tests and durations . 26
Table 8 – Preconditioning for technology/ manufacturing process change acceptance
testing . 27
Table 9 – Technology acceptance criteria for maximum allowable tin whisker length. 29
Table 10 – Manufacturing process change acceptance criteria for maximum allowable
tin whisker length . 29
Table A.1 – Test sample size requirements per precondition treatment for coupons . 37
Table A.2 – Optional preconditioning treatments for tin whisker test samples . 38
a
Table A.3 – Optional preconditioning reflow profiles . 38
Table A.4 – Tin whisker test conditions . 40
Table A.5 – Tin whisker tests standard report formats (general information) . 43
Table A.6 – Tin whisker tests standard report formats (detailed whisker information) . 45
Table A.7 – Whisker density ranges that can be determined based on the number of
whiskers observed per lead, termination, or coupon area . 46

62483 © IEC:2013 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
_____________
ENVIRONMENTAL ACCEPTANCE REQUIREMENTS
FOR TIN WHISKER SUSCEPTIBILITY OF TIN AND TIN ALLOY
SURFACE FINISHES ON SEMICONDUCTOR DEVICES

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
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
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patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 62483 has been prepared by IEC technical committee 47:
Semiconductor devices.
This first edition is based on JEDEC documents JESD201A and JESD22-A121A and replaces
IEC/PAS 62483, published in 2006. This first edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) The content of IEC/PAS 62483 was added to the content of JESD201A as Annex A.
b) A methodology was introduced for environmental acceptance testing of tin-based surface
finishes and mitigation practices for tin whiskers.
c) A Clause 6 was introduced detailing the reporting requirements of test results.

– 6 – 62483 © IEC:2013
The text of this standard is based on the following documents:
FDIS Report on voting
47/2171/FDIS 47/2180/RVD
Full information on the voting for the approval of this standard 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 stability 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.
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.
62483 © IEC:2013 – 7 –
INTRODUCTION
Many companies in the electronics industry have adopted tin-based surface finishes as one of
the methods to comply with various legislative lead-free (Pb-free) initiatives, e.g., the
European Union’s RoHS directive. However, tin (Sn) and tin alloy surface finishes may be
prone to tin whisker formation with associated possible reliability degradation. Appropriate
mitigation practices may be incorporated to reduce tin whisker propensity to an acceptable
level.
Test conditions in accordance with Annex A and qualification limits presented in this
International Standard are based on known Sn whisker data from around the world. These
test conditions have not been correlated with longer environmental exposures of components
in service. Thus, there is at present no way quantitatively to predict whisker lengths over long
time periods based on the lengths measured in the short-term tests described in this
document. At the time of writing, the fundamental mechanisms of tin whisker growth are not
fully understood and acceleration factors have not been established. Therefore, the testing
described in this document does not guarantee that whiskers will or will not grow under field
life conditions.
– 8 – 62483 © IEC:2013
ENVIRONMENTAL ACCEPTANCE REQUIREMENTS
FOR TIN WHISKER SUSCEPTIBILITY OF TIN AND TIN ALLOY
SURFACE FINISHES ON SEMICONDUCTOR DEVICES

1 Scope
This International Standard describes the methodology applicable for environmental
acceptance testing of tin-based surface finishes and mitigation practices for tin whiskers on
semiconductor devices. This methodology may not be sufficient for applications with special
requirements, (i.e. military, aerospace, etc.). Additional requirements may be specified in the
appropriate requirements (procurement) documentation.
This International Standard does not apply to semiconductor devices with bottom-only
terminations where the full plated surface is wetted during assembly (for example: quad-flat
no-leads and ball grid array components, flip chip bump terminations). Adherence to this
standard includes meeting the reporting requirements described in Clause 6.
2 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
2.1
base metal
metal alloy residing beneath all surface finish(es) and/or underplate

Surface finish
Underplate
(if applicable)
Base metal
IEC  2381/13
Figure 1 – Cross-sectional view of component surface finishes
2.2
tin and tin alloy surface finish
tin-based outer surface finish for external component terminations and other exposed metal
2.3
tin whisker mitigation practice
process(es) performed during the manufacture of a component to reduce the propensity for tin
whisker growth by minimizing the surface finish internal compressive stress

62483 © IEC:2013 – 9 –
2.4
manufacturing process change acceptance
acceptance testing of a change to a surface finish manufacturing process already accepted by
technology acceptance tests (qv)
2.5
similarity acceptance
acceptance of a change to a surface finish manufacturing process based upon similarity and
data available from previous tin whisker technology and manufacturing process change
acceptance tests
2.6
surface corrosion
localized change to a silver-coloured tin surface finish appearing in an optical microscope as
non-reflective dark spots ranging in size from about 25 µm on the longest dimension to the
entire termination
Note 1 to entry: While tin oxide is ubiquitous on tin surface finishes, surface corrosion creates a locally thick layer
of tin oxide that may span from the substrate to the surface of the deposit at the black spot. Typical photos of
termination corrosion are shown in Figure 2 (a) to d)).

– 10 – 62483 © IEC:2013
a) Matte Sn on Cu with Ni plate (optical)

b) Matte Sn on Cu (optical)
c) Matte Sn on Cu (SEM)
IEC  2383/13
d) Matte Sn on Cu (optical/SEM)
Figure 2 – Typical photographs of termination corrosion

62483 © IEC:2013 – 11 –
2.7
surface finish technology acceptance
acceptance testing of surface finish material set and manufacturing processes that includes a
defined set of base metals, underplating metals, surface finish alloy, surface finish bath
chemistry and process flow steps
2.8
underplate
underlay
plated layers between the base metal and the outer surface finish
2.9
whisker
spontaneous columnar or cylindrical filament, usually of monocrystalline metal, emanating
from the surface of a finish
EXAMPLE See Figure 3 for example pictures of tin whiskers.
Note 1 to entry: For the purposes of this document, whiskers have the following characteristics:
– they have an aspect ratio (length/width) greater than 2;
– they can be kinked, bent, or twisted;
– they usually have a uniform cross-sectional shape;
– they typically consist of a single columnar filament that rarely branches;
– they may have striations along the length of the column and/or rings around the circumference of the column;
– they have a length of 10 µm or more (features less than 10 µm may be deemed important for research but are
not considered significant for this test method).
Note 2 to entry: Whiskers are not to be confused with dendrites, fern-like growths on the surface of a material
which can be formed as a result of electromigration of an ionic species or produced during solidification. (See
Figure 4 for a picture of a typical solidification dendrite.)
b) Whisker with a consistent cross section
a) Tin whisker filaments
c) Kinked whisker
d) Kinked whiskers growing from a nodule

– 12 – 62483 © IEC:2013
e) Branched tin whiskers on bright tin (rare)
f) Whisker initiating from a hillock

g) Tin whisker filament with striations
h) Tin whisker filament with striations

j) Tin whisker with rings
i) Kinked whisker on odd-shaped eruptions
IEC  2384/13
Figure 3 – Examples of tin whiskers

62483 © IEC:2013 – 13 –
b) Hillocks may be precursors to whiskers
a) Dendrites are fern-like growths formed for
in some cases, but are not considered
example as a result of solidification.
whiskers for the purposes of
They are not whiskers
this test method
c) “Flower” created on a tin plating exposed to
the test condition of high-temperature

humidity storage and is most likely
d) Dendrites formed on a tin surface
a result of a combination of surface
during plating.
contamination and condensation
These are not tin whiskers
IEC  2385/13
Figure 4 – Non-whisker surface formations

2.10
whisker length
straight line distance from the point of emergence of the whisker to the most distant point on
the whisker
Note 1 to entry: The whisker length is the radius of a sphere containing the whisker with its centre located at the
point of emergence, see Figure 5.

Whisker
Whisker
length
Surface
IEC  2386/13
Figure 5 – Whisker length measurement

– 14 – 62483 © IEC:2013
2.11
whisker density
number of whiskers per unit area on a single lead or coupon area
2.12
whisker growth
measurable changes in whisker length and/or whisker density after exposure to a whisker test
condition for a certain duration or number of cycles
2.13
whisker test coupon
piece of metal of specified size and shape that is plated or dipped with a tin finish for the
purpose of measuring the propensity for whisker formation and growth
2.14
minimum lead-to-lead gap
minimum gap between leads (terminations)

IEC  2387/13
Figure 6 – Minimum lead-to-lead gap
2.15
matte tin
tin film with lower internal stresses and larger grain sizes typically of 1 µm or greater and
carbon content less than 0,050 %
2.16
bright tin
tin film with higher internal stresses and smaller grain size of 0,5 µm to 0,8 µm and carbon
content of 0,2 % to 1,0 %
3 Test method for measuring tin whisker growth
3.1 Procedure
Except as specifically noted in this document, the procedures for conducting stress testing
and inspections for tin whisker growth as shown in Annex A, shall be used as applicable to
satisfy this acceptance standard.
3.2 Test samples
In most cases, individual production components shall be used for the acceptance test.
However, for some assembled components with internal tin plated surfaces that cannot be
inspected optically, e.g., internal surfaces of cans and hybrid component lids, testing and
inspection of piece parts may be necessary. In addition, components with tin or tin alloy

62483 © IEC:2013 – 15 –
surface finishes used in press-fit, socketed applications, or with other compressive
mechanical connections, should be qualified in their end use configuration. Additional testing
and/or specifications may be needed for testing mechanically loaded components.
3.3 Handling precaution
Careful test sample handling is important in order to avoid possible damage or detachment of
whiskers from the test samples. Excessive vibration, impact, or physical contact with the
termination finish should be avoided because whiskers may be dislodged. Test sample
contamination as a result of improper handling or as a result of the application of a conductive
material for SEM inspection should be avoided if the samples are to be returned to the test
condition for further exposure, because such material may impact whisker growth behaviour.
The procedures outlined in Annex A to limit condensation on the samples should also be
followed during elevated temperature-humidity testing since condensation increases the
likelihood of surface corrosion.
3.4 Reflow assembly
The board assembly process shall reflect both the influence of typical reflow temperatures
and the metallurgical effects of a typical solder material. Components for which the
terminations are usually fully wetted, even with a board assembly process at the lower
process window limits, are exempted from this test. For example, this applies to:
– nonleaded components;
– flat leaded components.
Since whiskers usually grow only from the unwetted surface finish, it is essential that there is
some unwetted area left after the board assembly process. This area shall represent at least
1/3 of the termination surface. Technical justification (documentation) shall be provided that
the 1/3 minimum unwetted area requirement has been met, for example statistical EDX
analysis, etc. The number of sample terminations inspected needs to be increased due to the
reduction of termination area wetted by the board solder. The inspection increase should be
based on achieving approximately the same area as an unwetted termination. For example, if
only 1/3 of the termination area is unwetted, 3 times as many terminations shall be inspected
than for unassembled components, i.e. 96 × 3 = 288 per stress test.
The board assembly process will likely be somewhat different than typical production
assembly processes because of the requirement for minimum termination wetting. In cases
where the acceptance of multiple component types is being assessed by similarity (Tables 2
and 3), it is recommended that board assembly be performed on the component type with the
longest terminations in order to promote the presence of an unwetted surface. Table 1
provides some further guidance for the board assembly process that may help to minimize
termination wetting. Finally, it is recommended to clean the test board of flux residues before
acceptance testing due to the unknown effect of flux residues on whisker growth.

– 16 – 62483 © IEC:2013
b
Table 1 – SMT board assembly process guidance for minimum termination wetting
Reflow atmosphere Air
Flux type Low activity
Precondition C: SnPb
Paste alloy
Rrecondition D: SnAgCu
Substantial cut backs from production opening and/or thickness may be
Stencil
required
a
Reflow profile SnPb and Pb-free reflow profiles in accordance with Table A.3 and Figure A.2
a
In some cases it may be necessary to use a peak temperature at the low end of the range in order to avoid
substantial wetting of the terminations.
b
Boards do not need to be electrically functional.

4 Acceptance procedure for tin and tin alloy surface finishes
4.1 Determination of whether a technology, manufacturing process, or similarity
acceptance test is required
The acceptance requirements for tin and tin alloy finishes depend on the acceptance testing
history of the surface finish. For a surface finish without any acceptance testing history, a
rigorous technology acceptance test shall be completed as described in 4.3. If the tin or tin
alloy finish has already passed a technology acceptance test, then any change to the
manufacturing process or the metallurgy shall be categorized as either a technology change,
a manufacturing process change, or a negligible change based on similarity. Table 2 may be
used as guidance to differentiate between a technology and a manufacturing process
acceptance change. Table 3 shall be used to categorize a change as either a technology
change, a manufacturing process change, or a negligible change based on similarity. In
addition, Table 3 indicates required testing that is described in detail in Tables 4 to 8. The
acceptance procedure for tin and tin alloy surface finishes shall follow the procedural flow
outlined in Figure 7. A specific surface finish/mitigation process or change will necessitate a
technology or manufacturing process change acceptance unless the change is covered by
similarity. Figure 8 shows the typical technology acceptance test flow, using minimum sample
size, for multi-leaded components using copper alloy leadframe with post bake mitigation
technology.
62483 © IEC:2013 – 17 –
Surface finish
acceptance/change
procedure
New/change
Performance
Yes Pass
to a technology
technology Test
parameter
acceptance completed/write report
according to
testing
Table 2
Fail
Change lead
No
finish/re-quality
Change to
Performance
a manufacturing Yes Pass
manufacturing
Test
process parameter
process
completed/write report
according to
acceptance
Table 2
testing
Fail
Re-evaluate
process/re-quality
No
Acceptance by
similarity
IEC  2388/13
Figure 7 – Flowchart to determine whether a technology acceptance test,
a manufacturing process acceptance test or no testing is required
on the basis of similarity
– 18 – 62483 © IEC:2013
Screening
Detailed
inspection
inspection
2 samples
terminations
terminations
Lot 1
Precondition
Screening
Pass
Condition
(18
inspection
2 samples terminations
C
with the
terminations
Fail
longest
(SnPb reflow)
whiskers from
Screening
the combined
inspection
2 samples
lots 1,2 and 3)
terminations
Lot 2
Detailed
Screening
Temperature
inspection
inspection
cycling test
2 samples 18
terminations
terminations
Precondition
Screening
Pass
Condition
(18
inspection
2 samples
terminations
D
with the
Fail
terminations
longest
(Pb - free reflow)
Lot 3
whiskers from
Screening
the combined
inspection
lots 1,2 and 3)
2 samples
terminations
Repeat in accordance
with Table 6
Screening
Lot 1 Detailed
inspection
inspection
terminations
2 samples terminations
Precondition
Pass
Condition
Screening
Lot 2
Temperature
inspection (18
A
/humidity
32 terminations
Fail
storage test
terminations with the
2 samples
(No precondition)
longest
whiskers from
Screening
the combined
Lot 3
inspection
lots 1,2 and 3)
2 samples terminations
Repeat in accordance
with Table 6
IEC  2389/13
Figure 8 – Technology acceptance test flow for multi-leaded components using copper
alloy leadframe with post bake mitigation technology – Surface finish test sample,
technology parameters fixed (1 of 2)

62483 © IEC:2013 – 19 –
Screening
Detailed
inspection
inspection
2 samples
terminations
terminations
Lot 1
Precondition
Pass
Condition Screening
(18
inspection
2 samples
terminations
C
with the
Fail
terminations
longest
(SnPb reflow)
whiskers from
Screening
the combined
inspection
lots 1,2 and 3)
2 samples
terminations
Lot 2
High
Screening
Detailed
temperature
inspection
2 samples
inspection
/humidity
storage test
terminations
terminations
Precondition
Pass
Condition Screening
(18
inspection
2 samples
terminations
D
with the Fail
terminations
longest
(Pb - free reflow)
Lot 3
whiskers from
Screening
the combined
inspection
lots 1,2 and 3)
2 samples
terminations
Repeat in accordance
with Table 6
Pass technology acceptance test

IEC  2390/13
Figure 8 (2 of 2)
The acceptance requirements described in this document apply to a specific tin or tin alloy
surface finish. The same surface finish may originate from multiple plating lines and be used
on multiple component types, as long as the parameters described in Table 2 are the same.
For the purposes of this document, a surface finish is defined by the base metal, surface
finish composition, surface finish chemistry and manufacturing process, assembly process
and component type, and factory or plating process. These categories are listed in the left
column of Table 2. Within these categories, there are major parameters called technology
parameters and minor parameters called manufacturing process parameters that define the tin
or tin alloy surface finish. Any new surface finish shall be submitted for a technology
acceptance test. In addition, changes to technology parameters require a new technology
acceptance test, and changes to a manufacturing process parameter require a new
manufacturing process acceptance test, according to the flowchart in Figure 7.

– 20 – 62483 © IEC:2013
Table 2 – Surface finish technology and
manufacturing process change acceptance parameters
Parameter Technology parameters Manufacturing process parameters
• base metal composition • type, e.g., etched or stamped
Base metal
• surface finish alloy composition
Surface finish composition
• surface finish thickness
• underplate composition
• underplate thickness
• surface finish plating process • minor plating process control parameters
Surface finish chemistry or
manufacturing process
• process chemistry • dip process control parameters
• underplate process
• underplate process chemistry
• dip process
• dip process chemistry
• post bake process parameters
• plating bath vendor
• major plating process control
parameters
• lead forming process
Assembly process and
component type
• startup new factory • new plating equipment
Factory or plating process
Table 3 lists the technology and manufacturing process change acceptance tests required for
parameter changes. The details of the tests are described in Tables 4 to 8. Table 3 also
defines those changes that are considered negligible and do not require additional testing,
according to the flowchart in Figure 7.

62483 © IEC:2013 – 21 –
Table 3 – Tin and tin alloy surface finish acceptance test matrix
Acceptance tests required
Technology or
Qual
manufacturing Examples a
High/
type b
TC T&H
process parameter
T&H
Base metal
c
base metal alloy base metal, e.g., Cu alloy, FeNi42 T x x x
d
base metal vendor supplier A vs. B, same metal S – – –
leadframe type etch vs. stamped P x x x
Surface finish composition
Sn, SnAg3,5, SnBi2-4, SnBi5-7, SnCu1,
surface finish alloy T x x x
SnCu3
surface finish
T x x x
change in thickness limits
thickness
underplate
change in underplate composition T x x x
composition
underplate thickness change in thickness limits T x x x
Surface finish chemistry or process

in-line vs. rack vs. barrel,
surface finish plating
T x x x
process
bright vs. matte tin
underplate process change in underplate process T x x x
process chemistry MSA, mixed acid, etc. T x x x
plating bath vendor supplier A vs. B T x x x
change beyond process window limits for
major plating process
additive levels, metal content, acid content, T x x x
window limits
current density, temperature, impurity levels
change within process window limits for
minor plating process
additive levels, metal content, acid content, S – – –
window limits
current density, temperature, impurity levels
change of flux, impurity levels, immersion rate,
dip process T x x x
cooling rate, etc.
post bake process change in bake process parameters T x x x
Assembly process and component style
S – – –
lead form J-lead vs. gull wing
lead count different lead count S – – –
lead dimension e.g., 0,25 mm wide, 0,18 mm wide S – – –
e
Factory or plating process
f
P x x x
startup new factory new factory
T x x x
new plating line
accepted technology/factory/vendor
...