IEC 60194:2015

IEC 60194 ®
Edition 6.0 2015-04
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Printed board design, manufacture and assembly – Terms and definitions

Conception, fabrication et assemblage des cartes imprimées – Termes et
définitions
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IEC 60194 ®
Edition 6.0 2015-04
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Printed board design, manufacture and assembly – Terms and definitions

Conception, fabrication et assemblage des cartes imprimées – Termes et

définitions
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 31.180; 31.190 ISBN 978-2-8322-2592-9

– 2 – IEC 60194:2015 © IEC 2015
CONTENTS
FOREWORD . 6
INTRODUCTION . 8
1 Scope . 9
2 Normative references . 9
3 Terms and definitions . 9
4 A . 9
5 B . 23
6 C . 41
7 D . 71
8 E . 83
9 F . 93
10 G . 106
11 H . 109
12 I . 117
13 J . 122
14 K . 123
15 L . 125
16 M . 134
17 N . 145
18 O . 149
19 P . 154
20 Q . 175
21 R . 176
22 S . 188
23 T . 213
24 U . 225
25 V . 228
26 W . 232
27 X . 237
28 Y . 237
29 Z . 238
Annex A (informative) Principles and use of the classifiction code . 239
A.1 General . 239
A.2 Background. 239
A.3 List of codes . 240
Annex B (informative) Abbreviations . 243
B.1 – A – . 243
B.2 – B – . 243
B.3 – C – . 244
B.4 – D – . 246
B.5 – E – . 247
B.6 – F – . 248

B.7 – G – . 248
B.8 – H – . 248
B.9 – I – . 249
B.10 – J – . 249
B.11 – K – . 249
B.12 – L – . 249
B.13 – M – . 250
B.14 – N – . 251
B.15 – O – . 252
B.16 – P – . 252
B.17 – Q – . 253
B.18 – R – . 253
B.19 – S – . 254
B.20 – T – . 255
B.21 – U – . 256
B.22 – V – . 256
B.23 – W – . 256
B.24 – Z – . 256
Bibliography . 257

Figure 1 – Access hole . 11
Figure 2 – Alignment mark . 14
Figure 3 – Lands with anchoring spurs . 17
Figure 4 – Annular ring (annular width) . 18
Figure 5 – Area array . 19
Figure 6 – Simplified flow chart of printed board design/fabrication sequence . 20
Figure 7 – Aspect ratio (hole) . 21
Figure 8 – Asymmetric stripline . 22
Figure 9 – Axial lead . 23
Figure 10 – Back bonding . 24
Figure 11 – Back-bared land . 24
Figure 12 – Ball grid array (BGA) . 26
Figure 13 – Barrel crack . 27
Figure 14 – Example of feature location using baseline dimensions . 28
Figure 15 – Bathtub curve . 29
Figure 16 – Beam-lead device . 30
Figure 17 – Bifurcated solder terminal. 31
Figure 18 – Buried via and blind via . 33
Figure 19 – Bow . 36
Figure 20 – Breakaway . 37
Figure 21 – Bumped die . 39
Figure 22 – But plating joint (wrap plating) . 41
Figure 23 – Button plating . 41
Figure 24 – Castellation . 44
Figure 25 – Centre to centre spacing (pitch) . 44

– 4 – IEC 60194:2015 © IEC 2015
Figure 26 – Typical characteristic curve . 46
Figure 27 – Chip on board (COB) . 49
Figure 28 – Clearance hole . 51
Figure 29 – Clinched-wire through connection. 51
Figure 30 – Comb pattern . 53
Figure 31 – Conductor base spacing . 58
Figure 32 – Conductor spacing . 59
Figure 33 – Contact angle (soldering) . 61
Figure 34 – Crosshatching . 68
Figure 35 – Cup solder terminal . 69
Figure 36 – Dewetting . 76
Figure 37 – Example of an embedded component . 87
Figure 38 – Embedded passive component (device) . 88
Figure 39 – Etch factor . 90
Figure 40 – Etchback . 90
Figure 41 – Etching indicator . 91
Figure 42 – Fillet (adhesive) . 96
Figure 43 – Flag . 99
Figure 44 – Flare . 100
Figure 45 – Flip chip . 102
Figure 46 – Ground plane clearance . 109
Figure 47 – Heel fillet . 111
Figure 48 – Histogram . 112
Figure 49 – Hole, knee . 113
Figure 50 – Hole breakout . 113
Figure 51 – Hole void . 114
Figure 52 – Hook . 115
Figure 53 – Hook solder terminal . 115
Figure 54 – Layer-to-layer spacing . 128
Figure 55 – Leaded surface-mount component – Gull wing shaped lead . 129
Figure 56 – Magnification power parameters . 135
Figure 57 – Meniscus . 137
Figure 58 – Microstrip . 139
Figure 59 – Mirrored pattern . 141
Figure 60 – Nail heading . 145
Figure 61 – Negative etchback . 145
Figure 62 – Nonfunctional interfacial connection . 147
Figure 63 – Nonwetting . 148
Figure 64 – Normal distribution . 148
Figure 65 – Open point . 151
Figure 66 – Outgrowth, overhang and undercut. 152
Figure 67 – Outgrowth, overhang and undercut. 153
Figure 68 – Overlap (drill) . 153

Figure 69 – Passive array . 157
Figure 70 – Perforated (pierced) solder terminal . 159
Figure 71 – Pin grid array . 162
Figure 72 – Plated through-hole (PTH) . 164
Figure 73 – Primary flare . 170
Figure 74 – Primary taper . 170
Figure 75 – Resin recession . 181
Figure 76 – Printed board viewing orientations. 185
Figure 77 – Shadowing . 192
Figure 78 – Tape automated bonding . 214
Figure 79 – Tombstoned component . 221
Figure 80 – Turret solder terminal . 225
Figure 81 – Via planarization . 230
Figure 82 – Wrap plating . 237

– 6 – IEC 60194:2015 © IEC 2015
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
PRINTED BOARD DESIGN, MANUFACTURE AND ASSEMBLY –
TERMS AND DEFINITIONS
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
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
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with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
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between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
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5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
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6) All users should ensure that they have the latest edition of this publication.
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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.
International Standard IEC 60194 has been prepared by subcommittee 91: Electronics
assembly technology.
This sixth edition cancels and replaces the fifth edition, published in 2006 and constitutes a
technical revision.
The main changes with respect to the previous edition are the following: Some two hundred
terms and definitions have been updated, where applicable, and another two hundred new
terms and definitions have been added.
The text of this standard is based on the following documents:
FDIS Report on voting
91/1236/FDIS 91/1253/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.
– 8 – IEC 60194:2015 © IEC 2015
INTRODUCTION
This International Standard has been structured in such a way that for each letter of the
alphabet a new clause has been created. For the sake of comparison, the French version is
aligned to the English sequence and thus follows the alphabetical order of the English version.

PRINTED BOARD DESIGN, MANUFACTURE AND ASSEMBLY –
TERMS AND DEFINITIONS
1 Scope
This International Standard defines the terminology used in the field of printed circuit boards
and printed circuit board assembly products.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and
are indispensable for its application. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any
amendments) applies.
IEC 60050-541:1990, International Electrotechnical Vocabulary – Chapter 541: Printed
circuits
3 Terms and definitions
For the purposes of electronics assembly technology the terms and definitions from
IEC 60050-541 as well as the following apply.
The terms have been classified according to the decimal classification code (DCC) as
explained in Annex A.
4 A
54.1821
abrasion resistance
ability of a material to withstand surface wear
54.1318
abrasive trimming
adjusting the value of a film component by notching it with a finely adjusted stream of an
abrasive material against the resistor surface
40.1727
absorption coefficient
for a parallel beam of specified radiation in a given substance, the quantity µ describes the
abs
fraction of energy absorbed in passing through a thin layer of thickness ∆x
Note 1 to entry: The absorption coefficient is primarily energy dependent.
Note 2 to entry: According to whether the thickness ∆x is expressed in terms of length, mass per unit area, moles
per unit area or atoms per unit area, it is called the linear, mass, molar or atomic absorption coefficient.
Note 3 to entry: This entry was numbered 393-14-46 in IEC 60050-393:2003.
[SOURCE: IEC 60050-395:2014, 395-01-26]

– 10 – IEC 60194:2015 © IEC 2015
40.0087
absorptivity
ratio (or percentage) of the amount of energy absorbed by a substrate as
compared with the total amount of incident energy
93.0001
accelerated ageing
accelerated life test
test in which the parameters such as voltage and temperature are increased above normal
operating values to obtain observable or measurable deterioration in a relatively short period
of time
92.0011
accelerated equivalent soak
environmental soak of a component at a higher temperature for
a shorter time (compared to the standard soak), to provide roughly the same amount of
moisture absorption
Note 1 to entry: See also “soak".
93.0216
accelerated test
test to check the life expectancy of an electronic component or electronic assembly in a short
period of time by applying physically severe condition(s) to the unit under test
93.0260
acceleration factor
AF
ratio of stress in reliability testing to the normal operating condition
Note 1 to entry: This note applies to the French language only.
92.0288
acceptance inspection
inspection that determines conformance of a product to design specifications as
the basis for acceptance
90.0003
acceptance quality level
AQL
number of defects within a population (lot) at which the lot has the chance to be accepted with
an acceptance probability of about 90 % when testing a sample
Note 1 to entry: The number of defects is given in percent.
92.0004
acceptance tests
tests deemed necessary to determine the acceptability of a product as agreed to by both
buyer and vendor
60.1319
access hole
series of holes in successive layers of a multilayer board, each set having their centres on the
same axis
SEE: Figure 1.
Access hole
Land
IEC
Figure 1 – Access hole
Note 1 to entry: These holes provide access to the surface of the land on one of the layers of the board.
21.0005
access protocol
protocol, used at the user-network interface, to enable the user to employ the services and/or
facilities of a telecommunication network
[SOURCE: IEC 60050-716:1995, 716-04-18]
36.0006
accordion contact
type of connector contact that consists of a flat spring formed into a "Z" shape in order to
permit high deflection without overstress
90.0007
accuracy
degree to which the result of a measurement or calculation agrees with the true value
46.0009
acid flux
solution of an acid and an inorganic, organic, or water soluble organic flux
Note 1 to entry: See also inorganic flux, organic flux, and water soluble organic flux.
54.0010
acid number
acid value
number of milligrams of potassium hydroxide (KOH) required to neutralize the acid
components present in one gram of a liquid, under standardized conditions
[SOURCE: IEC 60050-212:2010, 212-18-15, modified – Instead of the term "neutralization
value", the term "acid value" has been used.]
46.0008
acid-core solder
wire solder with a self-contained acid flux
92.0021
acoustic microscope
equipment that creates an image using ultrasound to view a
specimen’s surface or subsurface features, including defects and damage
52.0011
actinic radiation
light energy that reacts with a photosensitive material in order to produce an image

– 12 – IEC 60194:2015 © IEC 2015
46.0012
activated rosin flux
mixture of rosin and small amounts of organic-halide or organic-acid activators
Note 1 to entry: See also “synthetic activated flux".
53.0013
activating
catalysing
initiating
seeding
sensitizing
treatment that renders nonconductive material receptive to electroless deposition
53.0014
activating layer
seed layer
layer of material that renders a nonconductive material receptive to electroless deposition
46.0015
activator
substance that improves the ability of a flux to remove surface oxides from the surfaces being
joined
30.0397
active desiccant
desiccant that is either fresh (new) or has been baked according to the manufacturer’s
recommendations to renew it to original specifications
30.0016
active device
electronic component whose basic character changes while operating on an applied signal
Note 1 to entry: This includes diodes, transistors, thyristors, and integrated circuits that are used for the
rectification, amplification, switching, etc., of analog or digital circuits in either monolithic or hybrid form.
36.0017
active metal
metal that has a very high electromotive force
54.1321
active trimming
adjusting the value of a film circuit element in order to obtain a specified functional output
from the circuit while it is electrically activated
90.0018
actual size
measured size
53.1322
additive process
chemically-deposited printed circuit
chemically-deposited printed wiring
process for obtaining conductive patterns by the selective deposition of conductive material
on unclad base material
Note 1 to entry: See also “semi-additive process” and “fully-additive process”.

[SOURCE: IEC 60050-541:1990, 541-04-03, modified – Two admitted terms "chemically-
deposited printed circuit" and "chemically-deposited printed wiring", as well as a note to entry
have been added.]
30.0019
add-on component
discrete or integrated packaged or chip components that are attached to a film circuit in order
to complete the circuit's function
42.2038
adhesion
bond produced by contact between pressure-sensitive adhesive
and a surface
46.1728
adhesive
non-metallic materials that can join solids by surface bonding and internal strength (adhesion
and cohesion)
Note 1 to entry: In surface mounting, an epoxy adhesive is used to adhere SMDs to the substrate.
[SOURCE: IEC 60050-212:2010, 212-15-44, modified – A note to entry has been added.]
96.0020
adhesion failure
rupture of an adhesive bond such that the separation appears to be at the adhesive-adherent
interface
74.0021
adhesion layer
metal layer that adheres a barrier metal to a metal land on the surface of an integrated circuit
53.0022
adhesion promotion
chemical process of preparing a surface to enhance its ability to be bonded to another surface
or to accept an over-plate
41.0438
adhesive coated substrate
base material upon which an adhesive coating is applied, for the purpose of retaining the
conductive material (either additively applied or attached as foil for subtractive processing),
that becomes part of a metal-clad dielectric
41.1320
adhesive-coated catalyzed laminate
base material with a thin polymer coating, that contains a plating catalyst, that is subsequently
treated in order to obtain a microporous surface
41.1323
adhesive-coated uncatalyzed laminate
base material with a thin polymer coating, that does not contain a plating catalyst, and is
subsequently treated in order to obtain a micro-porous surface
75.0558
adhesive transfer
transfer of adhesive from its normal position on the pressure
sensitive tape to the surface to which the tape was attached, either during unwind or removal

– 14 – IEC 60194:2015 © IEC 2015
96.0023
adsorbed contaminant
contaminant attracted to the surface of a material that is held captive in the form of a gas,
vapour or condensate
91.0024
advanced statistical method
statistical process analysis and control technique that is more sophisticated and less widely
applicable than basic statistical methods
90.0025
aging
ageing
change of a property with time
Note 1 to entry: For example solderability is a property.
Note 2 to entry: See also “accelerated aging”.
14.0027
air pollution
air contamination
contamination of the atmosphere with substances that are toxic or otherwise harmful
11.0849
algorithm
finite set of well-defined rules for the solution of a problem in a finite number of steps
[SOURCE: IEC 60050-714:1992, 714-21-02]
22.0030
alignment mark
stylized pattern that is selectively positioned on a substrate material to assist in alignment
SEE: Figure 2.
IEC
Figure 2 – Alignment mark
76.0031
aliphatic solvents
"straight chain" solvents, derived from petroleum, of low solvent power
76.0032
alkaline cleaner
material blended from alkali hydroxides and alkaline salts
33.0579
all metal package
hybrid circuit package made solely of metal, without glass or ceramic

75.0609
allowable temperature
temperature range in which an electronic circuit or component can perform its intended
functions
45.1947
alloy Sn-Bi
alloy that is used as a lead free solder and consisting of tin and bismuth as its
main constituents
Note 1 to entry: Sn-Bi58 has a low melting point of 138 °C, but is not widely used because of its brittle properties.
45.1948
alloy Sn-Cu
alloy that is used as a lead free solder consisting of tin and copper considered to
be applicable for wave or reflow soldering
45.1949
alloy Sn-Ag
alloy that is used as a lead free solder and consisting of tin and silver as its main
constituents used as a high temperature solder
45.1950
alloy Sn-Ag-Bi
alloy that is used as a lead free solder and consisting of tin, silver and
bismuth as its main constituents
Note 1 to entry: The Bi in Sn-Ag-Bi alloy reduces the melting temperature. The higher the Bi content, the higher
the mechanical strength, but with poorer elongation capacity. There is a limit to Bi content.
45.1951
alloy Sn-Ag-Cu
alloy that is used as a lead free solder consisting of tin, silver and copper
as its main constituents
45.1952
alloy Sn-Zn
alloy that is used as a lead free solder and consisting of tin and zinc as its main
constituents
Note 1 to entry: Zn09 alloy has the melting point of 199 °C, closest to the melting point of Sn-Pb alloy among lead
free solders, which allows soldering work at similar soldering temperatures, but tends to form a stable oxide film,
causing difficulty in securing a good solder wetting.
91.0033
alpha error
producer’s risk
size of a type I error or the probability of rejecting a hypothesis that is true
Note 1 to entry: See also type I error.
25.1729
alphanumerical
pertaining to data that contain the letters of an alphabet, the decimal digits, and that may
contain control characters, special characters and the space character
35.0612
alpha particle
He nucleus generated from a nuclear decay that is capable of generating hole-electron pairs
in microelectronic devices and switching cells causing soft errors in some devices

– 16 – IEC 60194:2015 © IEC 2015
21.1793
alternating current
AC
electric current that is a periodic function of time with a zero direct component or, by
extension, a negligible direct component
Note 1 to entry: For the qualifier AC, see IEC 60050-151.
Note 2 to entry: This note applies to the French language only.
[SOURCE: IEC 60050-131:2002, 131-11-24]
93.1324
alternative hypothesis
supposition that a significant difference exists between the desired results of two comparable
populations
Note 1 to entry: See also “null hypothesis” and “statistical hypothesis”.
43.1730
alumina substrate
aluminum oxide used as a ceramic substrate material
29.0034
ambient
surrounding environment coming into contact with the system or component in question
40.0035
amorphous polymer
polymer with a random and unstructured molecular configuration
21.0036
amplitude
maximum value of a voltage of an alternating voltage within one period
21.0037
a
...