IEC 60194-1:2021

Printed boards design, manufacture and assembly - Vocabulary - Part 1: Common usage in printed board and electronic assembly technologies

IEC 60194-1:2021 covers terms and definitions closely related with TC91 technology.
This document, together with IEC 60194-2:2017, cancel and replace IEC 60194:2015. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
1) exclusion of 32 general terms better served by other TCs;
2) exclusion of 47 terms no longer used by the electronic assembly industry;
3) inclusion of 14 new terms related with device embedded substrate technology;
4) inclusion of 113 synonymous terms;
5) removal of identification codes for terms and annexes.

Conception, fabrication et assemblage de cartes imprimées - Vocabulaire - Partie 1: Usage commun des techniques d’assemblage des composants électroniques et des cartes imprimées

L’IEC 60194-1:2021 spécifie les termes et définitions étroitement associés à la technique du TC 91.
Le présent document, ainsi que l’IEC 60194-2:2017, annulent et remplacent l’IEC 60194:2015. Cette édition constitue une révision technique.
Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente:
1) exclusion de 32 termes généraux convenant mieux à d’autres comités techniques;
2) exclusion de 47 termes qui ne sont plus utilisés dans le secteur de l’assemblage de composants électroniques;
3) inclusion de 14 nouveaux termes liés à la technique pour les substrats avec appareils intégrés;
4) inclusion de 113 termes synonymes;
5) suppression des codes d’identification des termes et des annexes.

General Information

• Status: Published
• Publication Date: 08-Feb-2021
• ICS: 31.180 - Printed circuits and boards
• ICS: 31.190 - Electronic component assemblies
• Technical Committee: TC 91 - Electronics assembly technology
• Drafting Committee: WG 5 - TC 91/WG 5
• Current Stage: PPUB - Publication issued
• Start Date: 05-Mar-2021
• Completion Date: 09-Feb-2021

Relations

• Replaces: IEC 60194:2015 - Printed board design, manufacture and assembly - Terms and definitions
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC 60194-1 ®
Edition 1.0 2021-02
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Printed boards design, manufacture and assembly – Vocabulary –
Part 1: Common usage in printed board and electronic assembly technologies

Conception, fabrication et assemblage de cartes imprimées – Vocabulaire –
Partie 1: Usage commun des techniques d’assemblage des composants
électroniques et des cartes imprimées

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IEC 60194-1 ®
Edition 1.0 2021-02
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Printed boards design, manufacture and assembly – Vocabulary –

Part 1: Common usage in printed board and electronic assembly technologies

Conception, fabrication et assemblage de cartes imprimées – Vocabulaire –

Partie 1: Usage commun des techniques d’assemblage des composants

électroniques et des cartes imprimées

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 31.180; 31.190 ISBN 978-2-8322-9353-9

– 2 – IEC 60194-1:2021 © IEC 2021
CONTENTS
FOREWORD . 5
INTRODUCTION . 7
1 Scope . 8
2 Normative references . 8
3 Terms and definitions . 8
3.1 A . 8
3.2 B . 20
3.3 C . 35
3.4 D . 59
3.5 E . 69
3.6 F . 78
3.7 G . 89
3.8 H . 92
3.9 I . 99
3.10 J . 104
3.11 K . 105
3.12 L . 106
3.13 M . 113
3.14 N . 121
3.15 O . 125
3.16 P . 130
3.17 Q . 146
3.18 R . 147
3.19 S . 157
3.20 T . 179
3.21 U . 190
3.22 V . 192
3.23 W . 196
3.24 X . 201
3.25 Y . 201
3.26 Z . 201

Figure 1 – Access hole . 9
Figure 2 – Alignment mark . 12
Figure 3 – Lands with anchoring spurs . 14
Figure 4 – Annular ring (annular width) . 15
Figure 5 – Area array . 16
Figure 6 – Simplified flow chart of printed board design/fabrication sequence . 17
Figure 7 – Aspect ratio (hole) . 18
Figure 8 – Asymmetric stripline . 19
Figure 9 – Axial lead . 20
Figure 10 – Back bonding . 20
Figure 11 – Back-bared land . 20
Figure 12 – Barrel crack . 22
Figure 13 – Example of feature location using baseline dimensions . 23

Figure 14 – Bathtub curve . 24
Figure 15 – Beam-lead device . 25
Figure 16 – Bifurcated solder terminal. 26
Figure 17 – Buried via and blind via . 27
Figure 18 – Bow . 30
Figure 19 – Breakaway . 31
Figure 20 – But plating joint (wrap plating) . 34
Figure 21 – Button plating . 35
Figure 22 – Castellation . 37
Figure 23 – Centre-to-centre spacing (pitch) . 38
Figure 24 – Typical characteristic curve . 39
Figure 25 – Clearance hole . 41
Figure 26 – Clinched-wire through connection. 42
Figure 27 – Comb pattern . 44
Figure 28 – Conductor Base Spacing . 47
Figure 29 – Conductor spacing . 48
Figure 30 – Contact angle (soldering) . 50
Figure 31 – Crosshatching . 57
Figure 32 – Cup solder terminal . 58
Figure 33 – Dewetting . 63
Figure 34 – Example of an embedded component . 72
Figure 35 – Embedded passive component (device) . 73
Figure 36 – Etch factor . 75
Figure 37 – Etchback . 76
Figure 38 – Etching indicator . 76
Figure 39 – Fillet, adhesive . 82
Figure 40 – Flag . 84
Figure 41 – Flare . 84
Figure 42 – Ground plane clearance . 91
Figure 43 – Head on pillow . 93
Figure 44 – Heel fillet . 94
Figure 45 – Knee hole . 95
Figure 46 – Hole breakout . 96
Figure 47 – Hole void . 97
Figure 48 – Hook . 97
Figure 49 – Hook solder terminal . 98
Figure 50 – Icicle . 99
Figure 51 – Layer-to-layer spacing . 109
Figure 52 – Magnification power parameters . 113
Figure 53 – Meniscus . 115
Figure 54 – Microstrip . 117
Figure 55 – Mirrored pattern . 118
Figure 56 – Nail heading . 121

– 4 – IEC 60194-1:2021 © IEC 2021
Figure 57 – Negative etchback . 122
Figure 58 – Nonfunctional interfacial connection . 123
Figure 59 – Nonwetting . 124
Figure 60 – Normal distribution . 125
Figure 61 – Open point . 127
Figure 62 – Outgrowth, overhang and undercut. 128
Figure 63 – Outgrowth, overhang and undercut. 129
Figure 64 – Overlap . 129
Figure 65 – Perforated (pierced) solder terminal . 133
Figure 66 – Plated through-hole (PTH) . 137
Figure 67 – Primary flare . 143
Figure 68 – Primary taper . 143
Figure 69 – Resin recession . 151
Figure 70 – Printed board viewing orientations. 155
Figure 71 – Shadowing . 161
Figure 72 – Tape automated bonding . 180
Figure 73 – Tombstoned component . 186
Figure 74 – Turret Solder Terminal . 190
Figure 75 – Via planarization . 195
Figure 76 – Wrap Plating . 201

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
PRINTED BOARDS DESIGN, MANUFACTURE AND ASSEMBLY –
VOCABULARY –
Part 1: Common usage in printed board
and electronic assembly technologies

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
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rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 60194-1 has been prepared by IEC technical committee 91:
Electronics assembly technology.
This document, together with IEC 60194-2:2017, cancel and replace IEC 60194:2015. This
edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) exclusion of 32 general terms better served by other TCs;
b) exclusion of 47 terms no longer used by the electronic assembly industry;
c) inclusion of 14 new terms related with device embedded substrate technology;
d) inclusion of 113 synonymous terms;
e) removal of identification codes for terms and annexes.

– 6 – IEC 60194-1:2021 © IEC 2021
The text of this International Standard is based on the following documents:
FDIS Report on voting
91/1688/FDIS 91/1705/RVD
Full information on the voting for the approval of this International Standard can be found in the
report on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts in the IEC 60194 series, published under the general title Printed boards design,
manufacture and assembly – Vocabulary, 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.
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
The committee decided to split the revision of IEC 60194:2015 into two separate documents:
IEC 60194-1 and IEC 60194-2. This document is the first part of the revision (IEC 60194-1). It
is composed of terms and definitions closely related with TC 91 technology.

– 8 – IEC 60194-1:2021 © IEC 2021
PRINTED BOARDS DESIGN, MANUFACTURE AND ASSEMBLY –
VOCABULARY –
Part 1: Common usage in printed board
and electronic assembly technologies

1 Scope
This part of IEC 60194 covers terms and definitions closely related with TC 91 technology.
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 60050 (all parts), International Electrotechnical Vocabulary
3 Terms and definitions
For the purposes of electronics assembly technology, the following terms and definitions apply.
3.1 A
3.1.1
abrasion resistance
ability of a material to withstand surface wear
3.1.2
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 Δx
Note 1 to entry: The absorption coefficient is primarily energy dependent.
Note 2 to entry: According to whether the thickness Δx 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]
3.1.3
absorptivity
ratio (or percentage) of the amount of energy absorbed by a substrate as compared
with the total amount of incident energy
3.1.4
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"
3.1.5
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
3.1.6
access hole
series of holes in successive layers of a multilayer board, each set having their centres on the
same axis
SEE: Figure 1
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.
3.1.7
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]
3.1.8
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
3.1.9
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 flux".
3.1.10
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 – The term "acid value" has been used
instead of the term "neutralization value".]

– 10 – IEC 60194-1:2021 © IEC 2021
3.1.11
acid-core solder
wire solder with a self-contained acid flux
3.1.12
acoustic microscope
equipment that creates an image using ultrasound to view a specimen's surface or subsurface
features, including defects and damage
3.1.13
actinic radiation
light energy that reacts with a photosensitive material in order to produce an image
3.1.14
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"
3.1.15
activating
catalysing
initiating
seeding
sensitizing
treatment that renders nonconductive material receptive to electroless deposition
3.1.16
activating layer
seed layer
layer of material that renders a nonconductive material receptive to electroless deposition
3.1.17
activator
substance that improves the ability of a flux to remove surface oxides from the surfaces being
joined
3.1.18
active desiccant
desiccant that is either fresh (new) or has been baked according to the manufacturer's
recommendations to renew it to original specifications
3.1.19
active metal
metal that has a very high electromotive force
3.1.20
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
3.1.21
actual size
measured size
3.1.22
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 terms "chemically deposited
printed circuit" and "chemically deposited printed wiring", as well as a note to entry, have
been added.]
3.1.23
adhesion
bond produced by contact between pressure-sensitive adhesive and
a surface
3.1.24
adhesion failure
rupture of an adhesive bond such that the separation appears to be at the adhesive-adherent
interface
3.1.25
adhesion layer
metal layer that adheres a barrier metal to a metal land on the surface of an integrated circuit
3.1.26
adhesion promotion
chemical process of preparing a surface to enhance its ability to be bonded to another surface
or to accept an over-plate
3.1.27
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
3.1.28
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
3.1.29
adhesive-coated catalyzed laminate
base material with a thin polymer coating, which contains a plating catalyst, that is subsequently
treated in order to obtain a microporous surface
3.1.30
adhesive-coated uncatalyzed laminate
base material with a thin polymer coating, which does not contain a plating catalyst, that is
subsequently treated in order to obtain a micro-porous surface.
3.1.31
adsorbed contaminant
contaminant attracted to the surface of a material that is held captive in the form of a gas,
vapour or condensate
– 12 – IEC 60194-1:2021 © IEC 2021
3.1.32
advanced statistical method
statistical process analysis and control technique that is more sophisticated and less widely
applicable than basic statistical methods
3.1.33
aging
ageing
change of a property (for example, solderability) with time
3.1.34
air pollution
air contamination
contamination of the atmosphere with substances that are toxic or otherwise harmful
3.1.35
algorithm
finite set of well-defined rules for the solution of a problem in a finite number of steps
[SOURCE: IEC 60050-171:2019, 171-05-07]
3.1.36
alignment mark
stylized pattern that is selectively positioned on a substrate material to assist in alignment
SEE: Figure 2
Figure 2 – Alignment mark
3.1.37
aliphatic solvents
"straight chain" solvents, derived from petroleum, of low solvent power
3.1.38
alkaline cleaner
material blended from alkali hydroxides and alkaline salts
3.1.39
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.

3.1.40
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
3.1.41
alloy
Sn-Ag
alloy that is used as a lead-free solder, consisting of tin and silver as its main
constituents, and used as a high-temperature solder
3.1.42
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 capability. There is a limit to Bi content.
3.1.43
alloy
Sn-Ag-Cu
alloy that is used as a lead-free solder consisting of tin, silver and copper
as its main constituents
3.1.44
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 present soldering temperatures, but tends to form a stable oxide film,
causing difficulty in securing a good solder wetting.
3.1.45
alpha error
producer's risk
size of a Type I error or the probability of rejecting a hypothesis that is true
3.1.46
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."
3.1.47
alumina substrate
aluminium oxide used as a ceramic substrate material
3.1.48
amorphous polymer
polymer with a random and unstructured molecular configuration

– 14 – IEC 60194-1:2021 © IEC 2021
3.1.49
anchoring spur
extension of a land on a flexible printed board that extends beneath the cover layer to assist in
holding the land to the base material
SEE: Figure 3
Figure 3 – Lands with anchoring spurs
3.1.50
angled bond
series of bonds for which the last one or several atoms are not aligned with the first ones
3.1.51
anisotropic conductive contact
electrical connection using an anisotropic conductive film or paste wherein conductive particles
of gold, silver, nickel, solder, etc. are dispersed
Note 1 to entry: When it is compressed, an electrical connection is attained only in the direction of compression.
3.1.52
annealed wire
wire that has been heated and slowly cooled to remove the effects caused by cold working
3.1.53
annotation
text, notes, or other identification, constructed by a computer-aided system, intended to be
inserted on a drawing, map or diagram
3.1.54
annular ring
annular width
portion of conductive material that completely surrounds a hole
SEE: Figure 4
Figure 4 – Annular ring (annular width)
3.1.55
anodic cleaning
reverse current cleaning
electrolytic cleaning in which the work is the anode
3.1.56
antipad
established clearance in the plane to accommodate a hole and its corresponding pad stack
3.1.57
aperture
opening in the stencil-foil
3.1.58
apparent field-of-view angle
angular subtense of the field-of-view in the image space of an optical system
3.1.59
arc resistance
tracking resistance
resistance of a material to the effects of a high-voltage, low-current arc (under prescribed
conditions) passing across the surface of the material
Note 1 to entry: The resistance is stated as a measure of total elapsed time at that voltage required to form a
conductive path on the surface; material carbonized by the arc.
3.1.60
architecture
structure of a computer's functional elements that enables it to possess specific maximum and
minimum capabilities
3.1.61
area array
bonding pattern in which edge and additional pads on the inner surface area of the chip are
addressed in the bonding scheme
SEE: Figure 5
– 16 – IEC 60194-1:2021 © IEC 2021

Figure 5 – Area array
3.1.62
area array tape automated bonding
tape automated bonding where some carrier tape terminations are made to lands within the
perimeter of the die
3.1.63
area ratio
ratio of the area of aperture opening to the area of aperture walls
3.1.64
array
group of elements or circuits arranged in rows and columns on a base material
3.1.65
artificial intelligence
capacity of a machine to perform functions that are normally associated with human intelligence
EXAMPLE Reasoning and learning.
3.1.66
artwork
accurately scaled configuration that is used to produce the "artwork master" or "production
master"
SEE: Figure 6
NOTE The term "original" can be used to preface any of the drafting and photographic-tooling terms used in this
figure. The "original" is not usually used in manufacturing processes. If a "copy" is made, the copy is of sufficient
accuracy to meet its intended purpose if it is to take on the name of any one of the terms used in this figure. Other
adjectives can also be used to help describe the kind of copy, i.e., "nonstable", "first generation," "record," etc.
Figure 6 – Simplified flow chart of printed board design/fabrication sequence
3.1.67
artwork master
photomaster
accurate configuration the scale of which is chosen as required to provide the necessary
accuracy, and which is used to produce the original production master
SEE: Figure 6
[SOURCE: IEC 60050-541:1990, 541-03-01, modified – The term "photomaster" and "SEE:
Figure 6" have been added.]
3.1.68
as-fired
condition of thick-film components or the surface condition of ceramic base materials after
having been processed in a firing furnace and prior to trimming or polishing

– 18 – IEC 60194-1:2021 © IEC 2021
3.1.69
aspect ratio
ratio of the length of a film component to its width
3.1.70
aspect ratio
ratio of the length or depth of a hole to its preplated diameter
SEE: Figure 7
Figure 7 – Aspect ratio (hole)
3.1.71
aspect ratio
ratio of aperture width to stencil thickness
3.1.72
assembly
assembled board
number of parts, subassemblies or combinations thereof joined together
Note 1 to entry: This term can be used in conjunction with other terms, for example, "printed circuit board assembly."
3.1.73
assembly drawing
document that depicts the physical relationship of two or more parts, a combination of parts and
subordinate assemblies, or a group of assemblies required to form an assembly of a higher
order
3.1.74
assembly language
machine-oriented language whose instructions are usually in one-to-one correspondence with
machine instructions and that can provide facilities such as the use of macroinstructions
Note 1 to entry: An assembly language generally uses symbolic naming of operations and locations.
[SOURCE: IEC 60050-171:1992, 171-05-15]
3.1.75
assembly manufacturer
individual, organization, or company responsible for the assembly process and verification
operations necessary to ensure full compliance of assemblies
3.1.76
asymmetric stripline
dual-strip line
stripline signal conductor that is embedded between two reference planes, but not centred
between them
SEE: Figure 8
Figure 8 – Asymmetric stripline
Note 1 to entry: The asymmetric stripline is also called "dual stripline".
3.1.77
attachment density
average number of surface mount or through-hole solder joints, based on pitch and land size,
that can be accommodated in a prescribed unit area (for example, cm ), considering land size
within the unit area to accommodate the solder joint attachment
3.1.78
attributes data
qualitative data that can be counted for recording and analysis purposes
3.1.79
automated component insertion
act or operation of assembling discrete components to printed boards by means of electronically
controlled equipment
3.1.80
automatic component placement
software that automatically optimizes the layout of components on a printed board
3.1.81
automatic conductor routing
software that automatically determines the placement of interconnections on a printed board
3.1.82
automatic dimensioning
computer-aided drafting function that automatically generates dimensions, leaders,
arrowheads, etc., that make up a complete set of documented dimensions
3.1.83
automatic test equipment
equipment that automatically analyses functional or static parameters in order to evaluate
performance
3.1.84
automatic test generation
computer generation of a test program based solely on circuit topology with little or no manual
programming effort
3.1.85
axial lead
lead wire extending from a component or module body along its longitudinal axis
SEE: Figure 9
– 20 – IEC 60194-1:2021 © IEC 2021

Figure 9 – Axial lead
3.1.86
azeotropic mixture
azeotrope
liquid mixture of two or more substances that behaves like a single substance
Note 1 to entry: The vapour produced by partial vaporization of the liquid has the same composition as the liquid.
3.2 B
3.2.1
back annotation
process of extracting appropriate information from a completed printed board design and
inserting it on the boards schematic diagram
3.2.2
back bonding
back mounting
attaching a die to a base material with its circuitry facing away from the base material
SEE: Figure 10
Figure 10 – Back bonding
3.2.3
back taper
constant decrease in diameter along the length of the body of a drill from the tip to the bottom
of the drill
3.2.4
back-bared land
land in flexible printed wiring that has a portion of the side normally bonded to the base dielectric
material exposed by a clearance hole
SEE: Figure 11
Figure 11 – Back-bared land
...