ISO 7582:2023

INTERNATIONAL ISO
STANDARD 7582
First edition
2023-02
Metallic coatings for electromagnetic
interference shielding — Designation
and characterization method
Revêtements métalliques pour le blindage contre les interférences
électromagnétiques — Désignation et méthode de caractérisation
Reference number
© ISO 2023
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Published in Switzerland
ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Designation . 2
4.1 General . 2
4.2 Shielding effectiveness of electromagnetic waves . 3
4.2.1 Frequency classification . 3
4.2.2 Electromagnetic interference shielding effectiveness . 3
4.3 Adhesion of metallic coatings . 4
4.3.1 General . 4
4.3.2 Peel strength . 4
4.3.3 Thermal cycle . 4
4.4 Substrate materials . 4
4.5 Metallic coatings . 5
4.6 Examples of designation . 5
5 Characterization methods .6
5.1 Electromagnetic interference shielding effectiveness . 6
5.2 Adhesion of metallic coatings . 6
5.3 Sampling . 7
Annex A (informative) Examples of shielding effectiveness measurement of metallic
coatings . 8
Annex B (informative) Examples of adhesion measurement of metallic coatings — Peel
strength and substrate surface roughness.14
Bibliography .19
iii
Foreword
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iv
Introduction
This document was developed to provide the designation of characteristics and the characterization
methods of metallic coatings for electromagnetic interference (EMI) shielding, in response to worldwide
demand for the standardization of such products.
ISO 17334 specifies the requirements for autocatalytic copper coatings plus nickel-phosphorous alloy
coatings on platable plastics or metallic materials, to provide EMI and electrostatic discharge (ESD)
shielding mainly for the housing of computers, telecommunication and other devices. However, varieties
of metallic coatings, which are not specified in ISO 17334, are used to provide higher EMI/ESD shielding
effectiveness in a wider frequency range. In particular, metallic coatings with a larger thickness or with
a higher permeability are used to provide higher EMI/ESD shielding effectiveness in automobile parts
and mobile communication devices.
A number of electronic controlling units (ECUs), motors and connectors are used in a car. Their housings
and covers are made from engineering plastics for mass reduction and varieties of metallic coatings are
applied to these parts to provide a high EMI/ESD shielding effectiveness.
v
INTERNATIONAL STANDARD ISO 7582:2023(E)
Metallic coatings for electromagnetic interference
shielding — Designation and characterization method
1 Scope
This document specifies the designation and the characterization methods metallic coatings that
provide electromagnetic interference (EMI) shielding for parts fabricated from plastics, ceramics,
glasses and other materials.
The designation consists of the EMI shielding effectiveness in a specific frequency range and the
adhesion of metallic coatings to the substrate, as well as the substrate material and the principal
component, manufacturing process and thickness of the metallic coatings.
The characterization methods consist of the methods to determine the EMI shielding effectiveness of
metallic coatings and those to evaluate the adhesion of metallic coatings to the substrate.
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.
ISO 472, Plastics — Vocabulary
ISO 2080, Metallic and other inorganic coatings — Surface treatment, metallic and other inorganic coatings
— Vocabulary
ISO 4525, Metallic coatings — Electroplated coatings of nickel plus chromium on plastics materials
ISO 16348, Metallic and other inorganic coatings — Definitions and conventions concerning appearance
IEC 60050, International electrotechnical vocabulary
ASTM B533, Standard test method for peel strength of metal electroplated plastics
JIS H 8630, Electroplated coatings on plastics materials for decorative purposes
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 472, ISO 2080, ISO 16348 and
IEC 60050 and the following apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
ABS
acrylonitrile-butadiene-styrene
plastic, based on terpolymers and/or blends of polymers and copolymers, made with acrylonitrile,
butadiene and styrene
[SOURCE: ISO 472:2013, 2.5]
3.2
EMI shielding effectiveness
electromagnetic interference effectiveness
ratio of voltage signals transmitted by the samples with and without metallic coatings for the same
incident power of electromagnetic waves
3.3
LCP
liquid crystal plastic
plastic material with the property of liquid crystal
3.4
PBT
polybutylene terephthalate
polymer made by the polycondensation of butylene glycol and terephthalic acid or dimethyl
terephthalate
[SOURCE: ISO 472:2013, 2.729]
3.5
PTFE
polytetrafluoroethylene
polymer of tetrafluoroethylene
[SOURCE: ISO 472:2013, 2.796]
3.6
TRL calibration method
through-reflect-line calibration method
calibration method to fix the systematic errors with the network analyser measurements using a zero-
length “through”, a longer “through” (called “line”) and high-reflect standards
3.7
VNA
vector network analyser
instrument to measure the transfer and/or impedance characteristics, that is, both magnitude and
phase changes, of a linear network, device, or material through stimulus response testing over a given
frequency range
4 Designation
4.1 General
A designation shall consist of the following:
a) the letters “SdM” as the elementary symbol indicating that the metallic coating has the ability for
EMI shielding effectiveness (see 4.2);
b) a letter designating the frequency band classification (see 4.3.1);
c) the letter “S” and a number designating the EMI shielding effectiveness (see 4.3.2) followed by a
solidus (/);
d) the letter “A” with lowercase letters designating the adhesion test method and a number designating
the adhesion of the metallic coatings (see 4.4) followed by a solidus (/);
e) letters designating the substrate materials (see 4.5) followed by a solidus (/);
f) an elemental symbol of the principal component element of the coatings with lowercase letters
designating the coating process (see 4.6);
g) a number indicating the minimum local thickness in micrometres, followed by a space when the
subsequent metallic coating is applied.
For multi-layered metallic coatings, designations f) and g) shall be repeated from the bottom to the top.
See 4.6 for examples of designations.
4.2 Shielding effectiveness of electromagnetic waves
4.2.1 Frequency classification
The letters shown in Table 1 shall designate the frequency bands of the electromagnetic waves under
consideration.
Table 1 — Designation of frequency bands under consideration
Designation Frequency band of the electromagnetic waves under General identification
a
consideration
Hz
b
A 50 to 60 Ultra-low frequency wave
3 4
B (3,0 × 10 ) to (3,0 × 10 ) Very low frequency wave
4 5
C (3,0 × 10 ) to (3,0 × 10 ) Low frequency wave
5 6
D (3,0 × 10 ) to (3,0 × 10 ) Medium wave
6 7
E (3,0 × 10 ) to (3,0 × 10 ) Short wave
7 8
F (3,0 × 10 ) to (3,0 × 10 ) Very high frequency wave
8 9
G (3,0 × 10 ) to (3,0 × 10 ) Ultra-high frequency wave
9 10
H (3,0 × 10 ) to (3,0 × 10 ) Centimetre wave
10 11
I (3,0 × 10 ) to (3,0 × 10 ) Millimetre wave
11 12
J (3,0 × 10 ) to (3,0 × 10 ) Sub-millimetre wave
a
Lower limit exclusive, upper limit inclusive.
b
Frequency of commercial power source.
4.2.2 Electromagnetic interference shielding effectiveness
The letter “S” and a number shall designate the EMI shielding effectiveness as shown in Table 2.
Table 2 — Designation of EMI shielding effectiveness
a
Designation Shielding effectiveness
dB
S- 31 or below
S35 31 to 35
S40 36 to 40
S50 41 to 50
S60 51 to 60
S70 61 to 70
S80 71 to 80
S90 above 80
a
Lower limit exclusive, upper limit inclusive.
4.3 Adhesion of metallic coatings
4.3.1 General
The letters shown in Table 3 and Table 4 shall designate the adhesion of metallic coatings.
Table 3 — Designation of peel strength test
a
Designation Peel strength
kN/m
A 1,0 1,0 or above
P
A 0,9 0,9 to 1,0
P
A 0,8 0,8 to 0,9
P
A 0,7 0,7 to 0,8
P
A 0,6 0,6 to 0,7
P
A 0,5 0,5 to 0,6
P
A 0,4 0,4 to 0,5
P
A 0,3 0,3 to 0,4
P
A - below 0,3
P
a
Lower limit inclusive, upper limit exclusive.
4.3.2 Peel strength
The letter “A” with a lowercase letter “P” and a number shall designate the adhesion of metallic coatings
evaluated by a peel test (see 5.2). The number designates the peel strength as shown in Table 3.
4.3.3 Thermal cycle
The letter “A” with lowercase letters “TC” and a number shall designate the adhesion of metallic coatings
assessed by a thermal cycle test as shown in Table 4. The number shall denote the service condition
number determining the condition of thermal cycle test as specified in ISO 4525 and shall show the test
condition in which the product does not constitute a failure (see 5.2).
Table 4 — Designation of thermal cycle test
Temperature limits
a
Designation Service condition number
°C
High Low
A 5 5 85 −40
TC
A 4 4 80 −40
TC
A 3 3 80 −30
TC
A 2 2 75 −30
TC
A 1 1 60 −30
TC
a
Service condition numbers in a thermal cycle test are defined in ISO 4525.
4.4 Substrate materials
The letters shown with lowercase letters as shown in Table 5 shall designate the substrate materials.
Table 5 — Designation of substrate materials
Designation Substrate material
a
PL Plastics
XXX
b
GL Glasses
b
CE Ceramics
b
OM Other materials
a
XXX should be replaced by the relevant abbreviated term for the plastics
material (see ISO 472 or Clause 3). For other materials, a conventional
abbreviated term should be shown accompanied by a note explaining the
abbreviated term in a separate line below the designation.
b
The note explaining the specific material may be given in a separate
line below the designation.
EXAMPLE 1 Polybutylene terephthalate is designated as PL .
PBT
EXAMPLE 2 Polyamide resin is designated as PL (where “PA” means polyamide resin).
PA
4.5 Metallic coatings
An elemental symbol shall designate the principal element of the metallic coating, i.e. those of metal
or alloy coatings, and the subsequent lowercase letters shall designate the coating processes as shown
in Table 6. The following number shall indicate the minimum local thickness of the metallic coating in
micrometres. The thickness shall be rounded off to one decimal place.
Table 6 — Processes for metallic coatings
Designation Process
VE Vacuum evaporation
SP Sputtering
a
EL Electroless plating
EP Electroplating
OP Other process
a
Electroless plating includes autocatalytic plating and immersion coating
(see ISO 2080).
4.6 Examples of designation
An autocatalytic copper coating of 1,0 μm thickness plus autocatalytic nickel-8 % phosphorous alloy
coating in thickness of 0,25 μm on an ABS substrate, which shows an electromagnetic shielding
effectiveness of 80 dB at frequencies from 30 MHz to 3 GHz and a coating adhesion assessed by the
thermal cycle test corresponding to service condition 2, shall have the following designation:
SdM F S80/A 2/PL / Cu 1,0 Ni 0,3
TC ABS EL EL
SdM G S80/A 2/PL / Cu 1,0 Ni 0,3
TC ABS EL EL
NOTE These coatings and their performance correspond to autocatalytic coating type 1 Grade 3 in
ISO 17334.
A sputter deposited copper coating of 0,6 micrometre thickness plus electroplated copper coating of
3,0 micrometre thickness plus electroplated nickel coating of 20,0 micrometre thickness on a PBT
substrate, which shows an electromagnetic shielding effectiveness of 72,7 dB and 101,4 dB at 1 GHz
and 100 GHz, respectively, and a peel strength of 0,89 kN/m, shall have the following designation (see
Annexes A and B):
SdM G S80/A 0,8/PL / Cu 0,6/ Cu 3,0 Ni 20,0
P PBT SP EP EP
SdM I S90/A 0,8/PL / Cu 0,6/ Cu 3,0 Ni 20,0
P PBT SP EP EP
An electrolessly deposited copper coating of 0,6 μm thickness, an electroplated copper coating of
3,0 μm thickness and an electroplated nickel coating of 1,0 μm thickness on a LCP substrate, shows an
electromagnetic shie
...