EN 13603:2021

SLOVENSKI STANDARD
01-september-2021
Nadomešča:
SIST EN 13603:2013
Baker in bakrove zlitine - Preskusne metode za ocenjevanje kakovosti zaščitnih
kositrovih prevlek na okroglih bakrovih vlečenih žicah za elektrotehniko
Copper and copper alloys - Test methods for assessing protective tin coatings on drawn
round copper wire for electrical purposes
Kupfer und Kupferlegierungen - Prüfverfahren zur Beurteilung von Schutzüberzügen aus
Zinn auf gezogenen Runddrähten aus Kupfer für die Anwendung in der Elektrotechnik
Cuivre et alliages de cuivre - Méthodes d’évaluation des revêtements en étain sur les fils
ronds étirés en cuivre pour usages électriques
Ta slovenski standard je istoveten z: EN 13603:2021
ICS:
25.220.40 Kovinske prevleke Metallic coatings
77.150.30 Bakreni izdelki Copper products
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 13603
EUROPEAN STANDARD
NORME EUROPÉENNE
May 2021
EUROPÄISCHE NORM
ICS 25.220.40; 77.150.30 Supersedes EN 13603:2013
English Version
Copper and copper alloys - Test methods for assessing
protective tin coatings on drawn round copper wire for
electrical purposes
Cuivre et alliages de cuivre - Méthodes d'évaluation des Kupfer und Kupferlegierungen - Prüfverfahren zur
revêtements en étain sur les fils ronds étirés en cuivre Beurteilung von Schutzüberzügen aus Zinn auf
pour usages électriques gezogenen Runddrähten aus Kupfer für die
Anwendung in der Elektrotechnik
This European Standard was approved by CEN on 12 April 2021.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 13603:2021 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
1 Scope . 4
2 Normative references . 4
3 Terms and definitions . 4
4 Thickness of the unalloyed tin coating . 5
4.1 General. 5
4.2 Principle of the method based on the electrolytic dissolution of the tin coating . 5
4.2.1 General. 5
4.2.2 Reagents and materials . 5
4.2.3 Apparatus . 5
4.2.4 Preparation of the test piece . 7
4.2.5 Procedure for determining the thickness of unalloyed tin coatings . 7
4.2.6 Expression of results . 10
4.3 Principle of the method based on XRF . 11
4.3.1 General. 11
4.3.2 Devices with measuring spots larger than the wire dia7meter — Overlap technique. 11
4.3.3 Devices with measuring spots smaller than the wire diameter – Full-spot technique . 12
4.3.4 Preparation of the test piece . 12
4.3.5 Factors affecting the measuring accuracy . 13
5 Continuity of the tin coating . 17
5.1 Principle . 17
5.2 Test solution . 17
5.3 Reference solution . 18
5.4 Preparation of the test piece . 18
5.5 Cleaning of the test piece . 18
5.6 Immersion for testing . 18
5.7 Determination . 19
5.7.1 General. 19
5.7.2 Comparison by Nessler cylinders . 19
5.7.3 Colorimetric method . 19
6 Adherence of the tin coating . 19
6.1 Principle . 19
6.2 Stock solution . 19
6.3 Test solution . 19
6.4 Preparation of the test piece . 19
6.5 Cleaning of the test piece . 20
6.6 Immersion for testing . 20
6.7 Examination . 20
7 Test report . 21
Bibliography . 22
European foreword
This document (EN 13603:2021) has been prepared by Technical Committee CEN/TC 133 “Copper and
copper alloys”, the secretariat of which is held by DIN.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by November 2021, and conflicting national standards
shall be withdrawn at the latest by November 2021.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN 13603:2013.
In comparison with the previous edition, the following technical modifications have been made:
— included the X-ray fluorescence analysis (XRF) to measure the thickness of the tin layer.
According to the CEN-CENELEC Internal Regulations, the national standards organisations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the
United Kingdom.
1 Scope
This document specifies methods for assessing the tin coating on drawn round copper wire for the
manufacture of electrical conductors, e.g. according to EN 13602.
This document includes test methods for the determination of the following characteristics:
a) thickness of the unalloyed tin coating;
b) continuity of the tin coating;
c) adherence of the tin coating.
WARNING — This document can involve the use of hazardous materials, operations, and equipment.
This document does not purport to address all of the safety problems associated with their use. It is the
responsibility of the user of this document to establish appropriate safety and health practices and
determine the applicability of regulatory limitations prior to use. Moreover this document does not
cover the aspects related to the people protection against the X-ray. To obtain information applicable to
this aspect, it is convenient to refer to national and international standards, and also to the local
regulations if they exist.
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.
EN 610, Tin and tin alloys - Ingot tin
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological 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
unalloyed tin coating
layer of pure tin on the surface of tinned wire
3.2
alloyed tin coating
diffusion layer of copper and tin formed at the copper wire and tin coating interface during tinning and
subsequent drawing and annealing processes
3.3
total tin coating
sum of the thicknesses of the unalloyed tin coating and the alloyed tin coating
3.4
measuring area
area of the surface over which a single measurement is made
3.5
X-ray fluorescence
XRF
secondary radiation occurring when a high intensity incident X-ray beam impinges upon a material
placed in the path of the incident beam
Note 1 to entry: The secondary emission has wavelengths and energies characteristic of that material.
[SOURCE: EN ISO 3497:2000-12, 2.1]
4 Thickness of the unalloyed tin coating
4.1 General
This document refers to two different methods to measure the thickness of the tin coating layers on
copper wires, the first one is based on the electrolytic dissolution of the tin layer. The second one is
based on the direct measure of the tin layer on the wires by means of the reflection of an X-ray beam on
its surface.
4.2 Principle of the method based on the electrolytic dissolution of the tin coating
4.2.1 General
Anodic dissolution of a well-defined area of the unalloyed coating using a suitable electrolyte, followed
by detection of the virtually complete dissolution of the unalloyed coating by a rapid change in cell
voltage. Calculation of the unalloyed coating thickness from the quantity of electricity (in coulombs)
used, which can in turn be calculated from:
a) the time interval between the start of the test and the first rapid change of cell voltage, if it is
conducted at constant current density; or
b) the integrated quantity of electricity used in dissolving the unalloyed coating.
4.2.2 Reagents and materials
4.2.2.1 Electrolyte, either a hydrochloric acid electrolyte or an electrolyte recommended by the
instrument manufacturer.
For the hydrochloric acid electrolyte, dilute 170 ml of hydrochloric acid (HCl), ρ = 1,18 g/ml, to 1 000 ml
with deionised water.
NOTE The unalloyed tin coating dissolves anodically at an efficiency of nearly 100 %; for determination of the
electrolyte efficiency, see 4.2.5.6.
WARNING — Hydrochloric acid causes burns and is irritating to the respiratory system. Avoid
breathing the vapour and prevent contact with eyes and skin.
This electrolyte dissolves tin coatings at very low cell voltages at which there is no anodic attack on the
substrates when they are exposed at the end of the test.
4.2.2.2 Tin, tin grade in accordance with EN 610.
4.2.3 Apparatus
Suitable instruments may be constructed from readily available components. Alternatively, a
proprietary instrument may be used.
4.2.3.1 Direct reading instruments
Proprietary direct reading instruments are available for use with electrolytes recommended by the
manufacturer.
The calculation of thickness of tin coating from current density is made electronically. The instrument
shall have some means of indicating when the unalloyed tin coating has been fully removed.
4.2.3.2 Other instruments
Instruments other than proprietary direct reading instruments record the quantity of electricity, in
coulombs, used in dissolving the unalloyed coating from the measuring area, usually in arbitrary units,
from which the thickness can be calculated using factors or tables.
4.2.3.3 Electrolytic cell
The electrolytic cell consists of a container for the electrolyte, a cathode and an anode, which is the test
piece. If the container is made of metal, such as stainless steel, the container can serve as the cathode. If
the container is made of insulating material, a separate cathode is required.
Also required are a device for supporting the appropriate length of the test piece and an agitation
mechanism. Depending on the wire diameter, the test piece may be a straight length of wire or, if
necessary to obtain sufficient surface area for smaller diameter wires, a holding device such as that
shown schematically in Figure 1 is required. A magnetic stirrer or similar system shall be used to
provide agitation.
Key
1 tee-frame to support test piece of non-conducting material, manufactured from nylon or other plastics
2 test piece
3 test piece connection (anode)
4 cathode connection
5 electrolyte level
6 test piece length L
7 electrolyte
8 non-metallic pin
9 cathode (stainless steel or lead), container (beaker)
Figure 1 — Alternative method for supporting fine wire or wire which cannot be straightened
4.2.4 Preparation of the test piece
Select a suitable length of test piece in order to provide the appropriate test piece area for exposure to
the electrolyte. If necessary, clean the test surface with a suitable organic solvent (see 5.5).
Care should be taken to avoid removal of metal during the cleaning operation.
4.2.5 Procedure for determining the thickness of unalloyed tin coatings
4.2.5.1 General
If commercial equipment is used, follow the manufacturer’s instructions with respect to the operating
procedure for measurement, the electrolyte and, if necessary, calibration. Appropriate attention shall be
given to the factors listed in 4.2.5.4. The performance of the instrument shall be checked using a
reference specimen of pure tin wire. A tin grade in accordance with EN 610 shall be used. The test shall
be carried out in accordance with 4.2.5.6.
If the instrument readings or the calculation of K give an electrolytic efficiency of equal to or greater
than 98 %, the instrument may be used without further adjustment. Otherwise, the cause of
discrepancy shall be remedied. Proprietary instruments shall be calibrated in accordance with the
manufacturer's instructions.
4.2.5.2 Determination of measuring area
The measuring area A in square centimetres is given by the Formula (1):
d ××L π
A= (1)
where
A is the measuring area in square centimetres;
d is the diameter of the test piece in millimetres;
L is the length of the test piece in millimetres.
For the determination of the measuring area, the length L of the test piece in millimetres shall be
determined with an accuracy of 1 % and the diameter d of the test piece for wires with a nominal
diameter of < 0,6 mm shall be determined with an accuracy of 1 % and for wires with a nominal
diameter of ≥ 0,6 mm with an accuracy of 0,5 %.
An exact area of stripping is necessary for accuracy and the main source of error is due to the meniscus
and current field at the electrolyte surface.
4.2.5.3 Electrolysis (Dissolution of the unalloyed tin coating)
The electrolyte (4.2.2.1) and test piece shall be introduced into the cell so that a known area is exposed
to the electrolyte. Efforts shall be made to ensure that no gas bubbles occur on the measuring area by
use of the agitation mechanism. The electrical connections shall be made and the agitator operated.
Electrolysis shall be continued until dissolution of the unalloyed tin coating is complete, as indicated by
a sharp change in the anode potential or cell voltage, or by the operation of the automatic cut-out.
After completion of the test, the test piece shall be removed from the cell, rinsed with water and
examined to ensure that complete removal of the unalloyed tin coating has occurred over the
measuring area (see 4.2.5.4.9).
4.2.5.4 Factors affecting the measuring accuracy
4.2.5.4.1 Coating thickness
The optimum accuracy is achieved with coating thicknesses in the range 0,2 μm up to 50 μm.
4.2.5.4.2 Current variation
For instruments using the constant current and time measuring technique, current variation will cause
errors. For instruments using a current-time integrator, too large a change in current can change the
anode current efficiency or interfere with the end-point, causing an error.
4.2.5.4.3 Area variation
The accuracy of the thickness measurement will be no better than the accuracy to which the measuring
area is known. Area variations due to electrolyte level (excessive agitation), can lead to measurement
errors. In some cases it can be advantageous to measure the length after electrolysis is complete and re-
calculate the area.
4.2.5.4.4 Agitation
Agitation (i.e. the rate of stirring) shall be sufficient to remove any gas bubbles formed during the test,
which can adhere to the test piece or cathode. Excessive agitation shall be avoided to prevent
interference with the length of test piece submerged.
4.2.5.4.5 Condition of the test piece surface
Oil, grease, paint, corrosion products, staining or other surface chemical treatments can interfere with
the test.
4.2.5.4.6 Cleanliness of the cell
Deposition of tin can take place on the cathode in some electrolytes. This deposit can alter the cell
voltages. It is, therefore, essential to keep the cathode clean.
4.2.5.4.7 Cleanliness of the electrical connections
In the case of instruments other than the constant current type, if the electrical connections are not
clean, the current/potential relationship will be disturbed and false end-points obtained.
4.2.5.4.8 Calibration standards
Measurements made using calibration standards are subject to the additional error of the calibration
standards.
4.2.5.4.9 Non-uniform dissolution
If the rate of dissolution is not uniform over the measuring area, a premature end-point can be obtained
and yield low results. Examination of the surface shall be made after the test (see 4.2.5.3) to verify that
most of the coating has dissolved.
The presence of other matter in the coating, the roughness of the coating surface and the presence of
porosity in the c
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