EN IEC 62496-2-5:2023

Optical circuit boards - Basic test and measurement procedures - Part 2-5: Flexibility test for flexible opto-electric circuits

This part of IEC 62496-2 defines a test method for folding flexibility inspection of flexible opto-electric circuits with a MIT folding endurance tester and presents a guideline for a step stress test method for finding the predetermined minimum mechanical folding radii below which the flexible opto-electric circuits can be damaged by intended folding distortion. Here, test samples are used instead of products for the flexibility test of their flexible opto-electric circuits, and the test samples have the same layer structure as the products.

Optische Leiterplatten - Grundlegende Prüf- und Messverfahren - Teil 2-5: Biegsamkeitstest für biegsame opto-elektrische Schaltkreise

Cartes à circuits optiques - Procédures fondamentales d’essais et de mesures - Partie 2-5: Essai de flexibilité pour les circuits optoélectriques souples

IEC 62496-2-5:2022 définit une méthode d’essai pour l’examen de la flexibilité au pliage des circuits optoélectriques souples au moyen d’un appareil de contrôle de la flexibilité, et fournit un guide qui présente une méthode d’essai sous contrainte échelonnée destinée à déterminer les rayons de pliage mécanique minimaux prédéterminés en deçà desquels les circuits optoélectriques souples peuvent être endommagés par la distorsion induite par un pliage intentionnel. Des échantillons d’essai sont utilisés ici à la place des produits pour l’essai de flexibilité de leurs circuits optoélectriques souples, et ces échantillons d’essai sont constitués du même matériau, ont la même structure de couches et utilisent la même technologie et les mêmes équipements de traitement que les produits eux-mêmes.

Plošče z optičnimi vezji - Osnovni preskusni in merilni postopki - 2-5. del: Preskušanje upogljivosti za zvijava optoelektrična vezja (IEC 62496-2-5:2022)

General Information

• Status: Published
• Publication Date: 19-Jan-2023
• ICS: 33.180.01 - Fibre optic systems in general
• Technical Committee: CLC/SR 86 - Fibre optics
• Drafting Committee: IEC/TC 86 - IEC_TC_86
• Current Stage: 6060 - Document made available - Publishing
• Start Date: 20-Jan-2023
• Completion Date: 20-Jan-2023
• Ref Project: SIST EN IEC 62496-2-5:2023 - Optical circuit boards - Basic test and measurement procedures - Part 2-5: Flexibility test for flexible opto-electric circuits (IEC 62496-2-5:2022)

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN IEC 62496-2-5:2023
01-marec-2023
Plošče z optičnimi vezji - Osnovni preskusni in merilni postopki - 2-5. del:
Preskušanje upogljivosti za zvijava optoelektrična vezja (IEC 62496-2-5:2022)

Optical circuit boards - Basic test and measurement procedures - Part 2-5: Flexibility test

for flexible opto-electric circuits (IEC 62496-2-5:2022)
Optische Leiterplatten - Grundlegende Prüf- und Messverfahren - Teil 2-5:
Biegsamkeitstest für biegsame opto-elektrische Schaltkreise (IEC 62496-2-5:2022)

Cartes à circuits optiques - Procédures fondamentales d’essais et de mesures - Partie 2-

5: Essai de flexibilité pour les circuits optoélectriques souples (IEC 62496-2-5:2022)

Ta slovenski standard je istoveten z: EN IEC 62496-2-5:2023
ICS:
31.180 Tiskana vezja (TIV) in tiskane Printed circuits and boards
plošče
33.180.01 Sistemi z optičnimi vlakni na Fibre optic systems in
splošno general
SIST EN IEC 62496-2-5:2023 en

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN IEC 62496-2-5:2023
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SIST EN IEC 62496-2-5:2023
EUROPEAN STANDARD EN IEC 62496-2-5
NORME EUROPÉENNE
EUROPÄISCHE NORM January 2023
ICS 33.180.01
English Version
Optical circuit boards - Basic test and measurement procedures
- Part 2-5: Flexibility test for flexible opto-electric circuits
(IEC 62496-2-5:2022)

Cartes à circuits optiques - Procédures fondamentales Optische Leiterplatten - Grundlegende Prüf- und

d'essais et de mesures - Partie 2-5: Essai de flexibilité pour Messverfahren - Teil 2-5: Biegsamkeitstest für biegsame

les circuits optoélectriques souples opto-elektrische Schaltkreise
(IEC 62496-2-5:2022) (IEC 62496-2-5:2022)

This European Standard was approved by CENELEC on 2023-01-11. CENELEC 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 CENELEC 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 CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the

same status as the official versions.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,

Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the

Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,

Türkiye and the United Kingdom.
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels

© 2023 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.

Ref. No. EN IEC 62496-2-5:2023 E
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SIST EN IEC 62496-2-5:2023
EN IEC 62496-2-5:2023 (E)
European foreword

The text of document 86/605/FDIS, future edition 1 of IEC 62496-2-5, prepared by IEC/TC 86 "Fibre

optics" was submitted to the IEC-CENELEC parallel vote and approved by CENELEC as

EN IEC 62496-2-5:2023.
The following dates are fixed:

• latest date by which the document has to be implemented at national (dop) 2023-10-11

level by publication of an identical national standard or by endorsement

• latest date by which the national standards conflicting with the (dow) 2026-01-11

document have to be withdrawn

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.

Any feedback and questions on this document should be directed to the users’ national committee. A

complete listing of these bodies can be found on the CENELEC website.
Endorsement notice

The text of the International Standard IEC 62496-2-5:2022 was approved by CENELEC as a

European Standard without any modification.

In the official version, for Bibliography, the following notes have to be added for the standard indicated:

IEC 60793-2-10 NOTE Harmonized as EN IEC 60793-2-10
IEC 60793-2-20 NOTE Harmonized as EN 60793-2-20
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SIST EN IEC 62496-2-5:2023
EN IEC 62496-2-5:2023 (E)
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications

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.

NOTE 1 Where an International Publication has been modified by common modifications, indicated by (mod), the

relevant EN/HD applies.

NOTE 2 Up-to-date information on the latest versions of the European Standards listed in this annex is available

here: www.cenelec.eu.
Publication Year Title EN/HD Year
IEC 60068-1 - Environmental testing - Part 1: General EN 60068-1 -
and guidance
IEC 60793-2 series Optical fibres - Part 2: Product EN IEC 60793-2 series
specifications
IEC 62496-2-1 - Optical circuit boards - Part 2-1: EN 62496-2-1 -
Measurements - Optical attenuation and
isolation
ISO 5626 1993 Paper - determination of folding endurance - -
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SIST EN IEC 62496-2-5:2023
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SIST EN IEC 62496-2-5:2023
IEC 62496-2-5
Edition 1.0 2022-12
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Optical circuit boards – Basic test and measurement procedures –
Part 2-5: Flexibility test for flexible opto-electric circuits
Cartes a circuits optiques – Procédures fondamentales d’essais et de mesures
Partie 2-5: Essai de flexibilité pour les circuits optoélectriques souples
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 33.180.01 ISBN 978-2-8322-6119-4

Warning! Make sure that you obtained this publication from an authorized distributor.

Attention! Veuillez vous assurer que vous avez obtenu cette publication via un distributeur agréé.

® Registered trademark of the International Electrotechnical Commission
Marque déposée de la Commission Electrotechnique Internationale
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SIST EN IEC 62496-2-5:2023
– 2 – IEC 62496-2-5:2022 © IEC 2022
CONTENTS

FOREWORD ........................................................................................................................... 4

1 Scope .............................................................................................................................. 6

2 Normative references ...................................................................................................... 6

3 Terms and definitions ...................................................................................................... 6

4 Apparatus ........................................................................................................................ 7

4.1 General description ................................................................................................. 7

4.2 Flexibility tester for flexibility test of FOECBs .......................................................... 8

4.2.1 FOECBs test sample of fibre optical types ....................................................... 8

4.2.2 FOECBs test sample of planer waveguide optical circuit types ........................ 8

4.3 O-E signal control source ........................................................................................ 9

4.4 Laser source ........................................................................................................... 9

4.5 Photo detector ........................................................................................................ 9

4.6 Folding jig ............................................................................................................... 9

4.7 Relay switch ......................................................................................................... 10

4.8 Main controller ...................................................................................................... 10

5 Test sample ................................................................................................................... 10

5.1 FOECB test samples of optical fibre-types ............................................................ 10

5.2 FOECB test samples of planar optical waveguide-types ........................................ 11

6 Procedures .................................................................................................................... 13

6.1 For test samples of optical fibre-types ................................................................... 13

6.1.1 Preparing test samples .................................................................................. 13

6.1.2 Initial optical and electrical performance measurement .................................. 13

6.1.3 Setting the test sample .................................................................................. 13

6.1.4 Flexibility measurement ................................................................................. 14

6.1.5 Final optical and electrical performance measurement ................................... 14

6.1.6 Mechanical performance measurement .......................................................... 14

6.2 For test samples of the planar optical waveguide-types......................................... 14

6.2.1 Preparing test samples .................................................................................. 14

6.2.2 Initial optical and electrical performance measurement .................................. 14

6.2.3 Setting the test sample .................................................................................. 15

6.2.4 Flexibility measurement ................................................................................. 15

6.2.5 Final optical and electrical performance measurement ................................... 15

6.2.6 Mechanical characteristic measurement ........................................................ 16

7 Report ........................................................................................................................... 16

Annex A (informative) Detail requirement for structure of FOECB test samples of

optical fibre-types ................................................................................................................. 17

Annex B (informative) Requirement for structure of FOECB test samples of planar

optical waveguide-types ........................................................................................................ 18

Annex C (informative) Guideline for flexibility folding jig setting conditions of FOECB

test samples ......................................................................................................................... 19

Bibliography .......................................................................................................................... 20

Figure 1 – Schematic diagram of flexible opto-electric circuit board (top view) ........................ 7

Figure 2 – Overview of the folding jig ...................................................................................... 8

Figure 3 – Schematic diagram of the flexibility test system for fibre optical circuits ................. 8

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SIST EN IEC 62496-2-5:2023
IEC 62496-2-5:2022 © IEC 2022 – 3 –

Figure 4 – Schematic diagram of the flexibility test system for planar waveguide optical

circuits .................................................................................................................................... 9

Figure 5 – Flexibility folding jigs (from the left, folding radius r is 1,0 mm, 2,0 mm, 3,0

mm, 4,0 mm, 5,0 mm and 10,0 mm) ...................................................................................... 10

Figure 6 – Schematic diagram of FOECB test samples of optical fibre-types ......................... 11

Figure 7 – Schematic diagram of FOECB test samples of planar optical waveguide-

types..................................................................................................................................... 12

Figure B.1 – Schematic diagram of the flexibility test system for planar waveguide

optical circuits ....................................................................................................................... 18

Figure C.1 – An example of measurement result of optical loss versus bending

diameter ............................................................................................................................... 19

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SIST EN IEC 62496-2-5:2023
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INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
OPTICAL CIRCUIT BOARDS –
BASIC TEST AND MEASUREMENT PROCEDURES –
Part 2-5: Flexibility test for flexible opto-electric circuits
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, Technical Reports,

Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their

preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with

may participate in this preparatory work. International, governmental and non-governmental organizations liaising

with the IEC also participate in this preparation. IEC collaborates closely 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

Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any

misinterpretation by any end user.

4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications

transparently to the maximum extent possible in their national and regional publications. Any divergence between

any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.

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

services carried out by independent certification bodies.

6) All users should ensure that they have the latest edition of this publication.

7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and

members of its technical committees and IEC National Committees for any personal injury, property damage or

other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and

expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC

Publications.

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.

IEC 62496-2-5 has been prepared by IEC technical committee 86: Fibre optics. It is an

International Standard.
The text of this International Standard is based on the following documents:
Draft Report on voting
86/605/FDIS 86/609/RVD

Full information on the voting for its approval can be found in the report on voting indicated in

the above table.
The language used for the development of this International Standard is English.
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SIST EN IEC 62496-2-5:2023
IEC 62496-2-5:2022 © IEC 2022 – 5 –

This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in

accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available

at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are

described in greater detail at www.iec.ch/standardsdev/publications.

A list of all parts in the IEC 62496 series, published under the general title Optical circuit boards,

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 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 document 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.
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SIST EN IEC 62496-2-5:2023
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OPTICAL CIRCUIT BOARDS –
BASIC TEST AND MEASUREMENT PROCEDURES –
Part 2-5: Flexibility test for flexible opto-electric circuits
1 Scope

This part of IEC 62496 defines a test method for folding flexibility inspection of flexible opto-

electric circuits with a flexibility tester endurance tester and presents a guideline for a step

stress test method for finding the predetermined minimum mechanical folding radii below which

the flexible opto-electric circuits can be damaged by intended folding distortion. Here, test

samples are used instead of products for the flexibility test of their flexible opto-electric circuits,

and the test samples have the same material, layer structure, processing technology and

equipment as the products.
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 60068-1, Environmental testing – Part 1: General and guidance
IEC 60793-2 (all parts), Optical fibres – Part 2: Product specifications

IEC 62496-2-1, Optical circuit boards – Part 2-1: Measurements – Optical attenuation and

isolation
ISO 5626:1993, Paper – Determination of folding endurance
3 Terms and definitions

For the purposes of this document, the terms and definitions given in IEC 62496-1 and the

following apply.

ISO and IEC maintain terminology databases for use in standardization at the following

addresses:
• IEC Electropedia: available at https://www.electropedia.org/
• ISO Online browsing platform: available at https://www.iso.org/obp
3.1
flexible opto-electric circuit board

flexible circuit board that contains both optic and electric circuits integrated into a flexible sheet

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SIST EN IEC 62496-2-5:2023
IEC 62496-2-5:2022 © IEC 2022 – 7 –
Figure 1 – Schematic diagram of flexible opto-electric circuit board (top view)

Note 1 to entry: Figure 1 shows an example of the top view of a flexible opto-electric circuit board.

Note 2 to entry: There are two types of flexible opto-electric circuit board: optical fibre-types and planer optical

waveguide-types.
[SOURCE: ISO 5626:1993, Clause 1]
3.2
flexibility tester

instrument for folding endurance test of flexible sheets with interchangeable folding heads,

allowing a range of thickness up to 1,25 mm
Note 1 to entry: In general, it is called the MIT folding endurance tester.
4 Apparatus
4.1 General description

The flexibility test system for flexibility test of the flexible opto-electric circuit board (hereafter

FOECB) shall be used for finding of the minimum folding radii of both optic and electric circuits

of the FOECB before any functional damage occurs. An existing flexibility folding method has

been used for testing the folding flexibility of only electric circuits. However, in this document,

it shall be used for testing the folding flexibility of both optic and electric circuits.

Since the test sample for fibre optical type should be connected to the flexibility test system

through an optical fibre, real-time monitoring may be possible. Accordingly, the flexibility tester

shall be configured with a real-time monitoring system using a laser signal device to accurately

know the time of breakage of the optical fibres.

Generally, test samples for planar waveguide optical circuits are difficult to measure through

real-time monitoring because it is not easy to connect to a flexibility test device through an

optical fibre. Therefore, the test sample should be tested by connecting only electric circuits as

in the existing flexibility folding method. The failure time of the test sample should be measured

separately using a visual light on the planar waveguide circuits.

But, in case of that the test sample for planar waveguide optical circuits shall use optical fibres

with connector to coupling with the optical waveguide, flexibility test of the test samples can be

possible with real-time monitoring.

In addition, these tests should be measured in the process of replacing the holding jig.The test

sample shall be clamped by the folding jig within the main controller as shown in Figure 2.

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SIST EN IEC 62496-2-5:2023
– 8 – IEC 62496-2-5:2022 © IEC 2022

a) Photograph diagram of the folding jig b) Photograph of a folding jig and test sample

Figure 2 – Overview of the folding jig
4.2 Flexibility tester for flexibility test of FOECBs
4.2.1 FOECBs test sample of fibre optical types

The flexibility test system for fibre optical circuits should be configured to stop the folding action

of the test sample if any damage starts to appear in its optical and electrical sections. Therefore,

the flexibility test system shall be composed of an optic-electric signal control source (hereafter

referred as O-E signal control source), test sample, and main controller, as shown in Figure 3.

Figure 3 – Schematic diagram of the flexibility test system for fibre optical circuits

4.2.2 FOECBs test sample of planer waveguide optical circuit types

The flexibility test system for planer waveguide optical circuits shall be constructed in the same

form as the folding flexibility test method for existing electrical circuits, as shown in Figure 4.

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SIST EN IEC 62496-2-5:2023
IEC 62496-2-5:2022 © IEC 2022 – 9 –
Figure 4 – Schematic diagram of the flexibility test system
for planar waveguide optical circuits
4.3 O-E signal control source

An O-E signal control source shall be composed of a laser source, photo detector, relay switch,

electric power source, optical fibre, and optical connectors. The O-E signal control source

supplies an optical signal to the test sample, and allows the photo detector to control the relay

switch based on detected optical signal for on-off switching of the electric signal flow (current)

within the flexibility test system.
4.4 Laser source

The optical output power of the laser source shall have enough larger of the minimum detected

power of optical detector and attenuation (optical loss) of samples. The laser source in the O-

E signal control source sends an optical signal to the test sample via its optical input terminal

connected to the protruded optical fibre. The wavelength and mode of the laser source should

be chosen according to the application to be used. The launching mode of the laser source

should be appropriate to the application of the relevant specification of O-E circuit board.

4.5 Photo detector

The minimum detected optical power of the photo detector shall be enough to detect the optical

power after attenuating the optical power by the test sample and light source power. The photo

detector detects the optic signal flow in the test sample. The photo detector output controls the

relay switch inside the O-E signal control source. Therefore, the output current of the photo

detector should be above the minimum operating voltage of the relay switch with a proper

resistance for the current output. The photo detector shall have enough response frequency to

detect the optical power change (deviation) by the attenuation change caused by the folding

distortion. At minimum, the response frequency for the photo detector should be 10 times or

more than the folding duration (0° to 90°), or kHz order will be necessary.
4.6 Folding jig

The size of the jig shall be selected according to the test samples. Several types of folding jigs

with different bending radii are required to apply various bending tests to the test sample.

Folding jigs of 6 different curvature radii (1,0 mm, 2,0 mm, 3,0 mm, 4,0 mm, 5,0 mm, and

10,0 mm) should be prepared (see Figure 5).
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Figure 5 – Flexibility folding jigs (from the left, folding radius r is
1,0 mm, 2,0 mm, 3,0 mm, 4,0 mm, 5,0 mm and 10,0 mm)
4.7 Relay switch

The switching time shall be at least one tenth of the folding speed. The relay switch plays a role

of direct on-off switching control of the electric circuit in the flexibility test system. That is, once

the photo detector detects the optic signal flow in the test sample, the relay switch stays in the

on-state. If the photo detector fails to detect the optic signal flow in the test sample, the relay

switch turns to the off-state. The relay switch operates the flexibility test system depending on

the detected optical signal output at the photo detector, which is subject to the physical state

of the test sample (e.g., either broken or non-broken state of the optic circuit).

4.8 Main controller

The main controller shall control the electrical current to fold the folding jig with enough

accuracy to test. The main controller supplies an electric current to the test sample and

mechanically controls the folding action of the test sample. The main controller may consist of

the main controller and the mechanical control means of folding, separately. Generally, the

main controller emits the electric signal by itself to perform the mechanical folding operation on

the test sample. The typical electric current flowing through the main controller ranges from

1 mA to 10 mA.
5 Test sample
5.1 FOECB test samples of optical fibre-types

Test samples of optical fibre-types shall have a pigtailed shape (see Figure 6). The optical

fibres used in the test samples may be single-mode and/or multimode fibres. Depending on

applications, glass optical fibres, polymer optical fibres, and specialty optical fibres may be

used to form the optical circuits.

The optical circuits shall be positioned at a central part of the entire FOECB test samples. The

electrical circuits shall be positioned at peripheral areas of the optical circuit in a symmetrical

structure. The symmetrical structure shall have superior characteristics in size stability from the

viewpoint of design and reliability for the FOECB test samples, as shown in Figure 6.

The test samples of the optical fibre-types shall have a protruded structure with a length of l9

at one side. The protruded length (l ) shall be maintained with sufficient length over 100 mm

for easy connection with other fibres (e.g., fibre fusion splicing). The other side of the test

samples shall have a continuous fibre bending area over a 6-mm diameter with a non-end state

as shown in Figure 6. The bending state over the 6-mm diameter for glass optical fibres shall

be maintained to minimize their optical bending loss.
A detail requirement for structure of FOECB test
...

SLOVENSKI STANDARD
oSIST prEN IEC 62496-2-5:2022
01-februar-2022
Plošče z optičnimi vezji - Osnovni preskusni in merilni postopki - 2-5. del:
Preskušanje upogljivosti za zvijava optoelektrična vezja

Optical circuit boards - Basic test and measurement procedures - Part 2-5: Flexibility test

for flexible opto-electric circuits
Ta slovenski standard je istoveten z: prEN IEC 62496-2-5:2021
ICS:
31.180 Tiskana vezja (TIV) in tiskane Printed circuits and boards
plošče
33.180.01 Sistemi z optičnimi vlakni na Fibre optic systems in
splošno general
oSIST prEN IEC 62496-2-5:2022 en

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST prEN IEC 62496-2-5:2022
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oSIST prEN IEC 62496-2-5:2022
86/591/CDV
COMMITTEE DRAFT FOR VOTE (CDV)
PROJECT NUMBER:
IEC 62496-2-5 ED1
DATE OF CIRCULATION: CLOSING DATE FOR VOTING:
2021-12-17 2022-03-11
SUPERSEDES DOCUMENTS:
86/570/CD, 86/582A/CC
IEC TC 86 : FIBRE OPTICS
SECRETARIAT: SECRETARY:
United States of America Mr Steve Swanson
OF INTEREST TO THE FOLLOWING COMMITTEES: PROPOSED HORIZONTAL STANDARD:
TC 86,SC 86B,TC 91
Other TC/SCs are requested to indicate their interest, if
any, in this CDV to the secretary.
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CENELEC, is drawn to the fact that this Committee Draft
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TITLE:

Optical circuit boards - Basic test and measurement procedures - Part 2-5: Flexibility test for

flexible opto-electric circuits
PROPOSED STABILITY DATE: 2026
NOTE FROM TC/SC OFFICERS:

Formerly IEC 62496-2-61. Numbering change approved by Plenary decision (see 86/577/RM, Decision

2020-03).

Copyright © 2021 International Electrotechnical Commission, IEC. All rights reserved. It is permitted to download this

electronic file, to make a copy and to print out the content for the sole purpose of preparing National Committee positions.

You may not copy or "mirror" the file or printed version of the document, or any part of it, for any other purpose without

permission in writing from IEC.
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1 CONTENTS

3 FOREWORD .......................................................................................................................... 4

4 1 Scope ............................................................................................................................. 6

5 2 Normative references ...................................................................................................... 6

6 3 Terms and definitions ..................................................................................................... 6

7 4 Apparatus ....................................................................................................................... 7

8 4.1 General description ................................................................................................ 7

9 4.2 MIT tester for flexibility test of FOECBs .................................................................. 7

10 4.2.1 FOECBs test sample of fibre optical types ...................................................... 7

11 4.2.2 FOECBs test sample of planer waveguide optical circuit types ........................ 8

12 4.3 O-E signal control source ....................................................................................... 8

13 4.4 Laser source .......................................................................................................... 8

14 4.5 Photo detector........................................................................................................ 8

15 4.6 Folding jig .............................................................................................................. 9

16 4.7 Relay switch ........................................................................................................... 9

17 4.8 Main controller ....................................................................................................... 9

18 5 Test sample .................................................................................................................... 9

19 5.1 FOECB test samples of optical fibre-types ............................................................. 9

20 5.2 FOECB test samples of planar optical waveguide-types ....................................... 10

21 6 Procedures ................................................................................................................... 11

22 6.1 For test samples of optical fibre-types .................................................................. 11

23 6.1.1 Preparing test samples ................................................................................. 11

24 6.1.2 Initial optical and electrical performance measurement ................................. 12

25 6.1.3 Setting the test sample ................................................................................. 12

26 6.1.4 Flexibility measurement ................................................................................ 12

27 6.1.5 Final optical and electrical performance measurement .................................. 12

28 6.1.6 Mechanical performance measurement ......................................................... 13

29 6.2 For test samples of the planar optical waveguide-types ........................................ 13

30 6.2.1 Preparing test samples ................................................................................. 13

31 6.2.2 Initial optical and electrical performance measurement ................................. 13

32 6.2.3 Setting the test sample ................................................................................. 13

33 6.2.4 Flexibility measurement ................................................................................ 14

34 6.2.5 Final optical and electrical performance measurement .................................. 14

35 6.2.6 Mechanical characteristic measurement ........................................................ 14

36 7 Report .......................................................................................................................... 14

37 Annex A (informative) Detail requirement for structure of FOECB test samples of optical

38 fibre-types .................................................................................................................... 15

39 Annex B (normative) Requirement for structure of FOECB test samples of planar optical

40 waveguide-types ........................................................................................................... 16

41 Annex C (informative) Guideline for MIT folding jig setting conditions of FOECB test

42 samples ........................................................................................................................ 17

43 Bibliography ......................................................................................................................... 18

45 Figure 1 – Schematic diagram of flexible opto-electric circuit board (top view) ....................... 6

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Figure 2 – Overview of the folding jig ..................................................................................... 7

47 Figure 3 – Schematic diagram of the MIT test system for fibre optical circuits ........................ 8

48 Figure 4 – Schematic diagram of the MIT test system for planar waveguide optical circuits .... 8

49 Figure 5 – MIT folding jigs (from the left, folding radius r is 1,0 mm, 2,0 mm, 3,0 mm,

50 4,0 mm, 5,0 mm and 10,0 mm) ............................................................................................... 9

51 Figure 6 – Schematic diagram of FOECB test samples of optical fibre-types ........................ 10

52 Figure 7 – Schematic diagram of FOECB test samples of planar optical waveguide-types .... 11

53 Figure B.1 – Schematic diagram of the MIT test system for planar waveguide optical

54 circuits ................................................................................................................................. 16

55 Figure C.1 – An example of measurement result of optical loss versus bending diameter ..... 17

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59 INTERNATIONAL ELECTROTECHNICAL COMMISSION
60 ____________
62 OPTICAL CIRCUIT BOARDS – BASIC TEST AND MEASUREMENT
63 PROCEDURES
65 Part 2-5: Flexibility test for flexible opto-electric circuits
67 FOREWORD

68 1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising all

69 national electrotechnical committees (IEC National Committees). The object of IEC is to promote international co-

70 operation on all questions concerning standardization in the electrical and electronic fields. To this end and in addition

71 to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports, Publicly

72 Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their preparation is

73 entrusted to technical committees; any IEC National Committee interested in the subject dealt with may participate in

74 this preparatory work. International, governmental and non-governmental organizations liaising with the IEC also

75 participate in this preparation. IEC collaborates closely with the International Organization for Standardization (ISO)

76 in accordance with conditions determined by agreement between the two organizations.

77 2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international

78 consensus of opinion on the relevant subjects since each technical committee has representation from all interested

79 IEC National Committees.

80 3) IEC Publications have the form of recommendations for international use and are accepted by IEC National

81 Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC

82 Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any misinterpretation

83 by any end user.

84 4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications

85 transparently to the maximum extent possible in their national and regional publications. Any divergence between any

86 IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.

87 5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity

88 assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any services

89 carried out by independent certification bodies.

90 6) All users should ensure that they have the latest edition of this publication.

91 7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and members

92 of its technical committees and IEC National Committees for any personal injury, property damage or other damage

93 of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and expenses arising out of

94 the publication, use of, or reliance upon, this IEC Publication or any other IEC Publications.

95 8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is

96 indispensable for the correct application of this publication.

97 9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent

98 rights. IEC shall not be held responsible for identifying any or all such patent rights.

99 IEC 62496-2-5 has been prepared by IEC technical committee 86: FIBRE OPTICS. It is an

100 International Standard.
101 The text of this International Standard is based on the following documents:
Draft Report on voting
86/XX/FDIS 86/XX/RVD
102

103 Full information on the voting for its approval can be found in the report on voting indicated in the

104 above table.

105 The language used for the development of this International Standard is English.

106 This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in

107 accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available at

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108 www.iec.ch/members_experts/refdocs. The main document types developed by IEC are described

109 in greater detail at www.iec.ch/standardsdev/publications.

110 The committee has decided that the contents of this document will remain unchanged until the

111 stability date indicated on the IEC website under webstore.iec.ch in the data related to the specific

112 document. At this date, the document will be
113 • reconfirmed,
114 • withdrawn,
115 • replaced by a revised edition, or
116 • amended.
117
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118 OPTICAL CIRCUIT BOARDS – BASIC TEST AND MEASUREMENT
119 PROCEDURES
120
121 Part 2-5: Flexibility test for flexible opto-electric circuits
122
123 1 Scope

124 This part of IEC 62496-2 defines a test method for folding flexibility inspection of flexible opto-

125 electric circuits with a MIT folding endurance tester and presents a guideline for a step stress test

126 method for finding the predetermined minimum mechanical folding radii below which the flexible

127 opto-electric circuits can be damaged by intended folding distortion. Here, test samples are used

128 instead of products for the flexibility test of their flexible opto-electric circuits, and the test samples

129 have the same layer structure as the products.
130 2 Normative references

131 The following documents are referred to in the text in such a way that some or all of their content

132 constitutes requirements of this document. For dated references, only the edition cited applies. For

133 undated references, the latest edition of the referenced document (including any amendments)

134 applies.
135 IEC 60068-1, Environmental testing – Part 1: General and guidance
136 IEC 60793-2 (all parts), Optical fibres – Part 2: Product specifications

137 IEC 62496-2-1, Optical circuit boards - Part 2-1: Measurements - Optical attenuation and isolation

138 ISO 5626:1993, Paper – Determination of folding endurance
139 3 Terms and definitions

140 For the purposes of this document, the terms and definitions defined in IEC 62496-1 and the

141 following apply.

142 ISO and IEC maintain terminological databases for use in standardization at the following

143 addresses:
144 • ISO Online browsing platform: available at https://www.iso.org/obp
145 • IEC Electropedia: available at http://www.electropedia.org/
146 3.1
147 flexible opto-electric circuit board

148 flexible circuit board that contains both optic and electric circuits integrated into a flexible sheet

149 Note 1 to entry: Figure 1 shows an example of the top view of a flexible opto-electric circuit board.

150

151 Figure 1 – Schematic diagram of flexible opto-electric circuit board (top view)

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152 3.2
153 MIT test system

154 instrument for folding endurance test of flexible sheets with interchangeable folding heads, allowing

155 a range of thickness up to 1,25 mm

156 Note 1 to entry: The name of the MIT folding endurance tester follows the Massachusetts Institute of Technology because

157 it has been developed by the institute.

158 Note 2 to entry: There are two types of flexible opto-electric circuit board: optical fibre-types and planer optical waveguide-

159 types.
160 [SOURCE: ISO 5626:1993, Clause 1]
161 4 Apparatus
162 4.1 General description

163 The MIT test system for flexibility test of the flexible opto-electric circuit board (hereafter FOECB)

164 shall be used for finding of the minimum folding radii of both optic and electric circuits of the FOECB

165 before any functional damage occurs. An existing MIT folding method has been used for testing

166 the folding flexibility of only electric circuits. However, in this proposed standard, it shall be used

167 for testing the folding flexibility of both optic and electric circuits.

168 Since the test sample for fibre optical type should be connected to the MIT test system through an

169 optical fibre, real-time monitoring may be possible. Accordingly, the MIT tester shall be configured

170 with a real-time monitoring system using a laser signal device to accurately know the time of

171 breakage of the optical fibres.

172 Test samples for planar waveguide optical circuits are difficult to measure through real-time

173 monitoring because it is not easy to connect to an MIT test device through an optical fibre.

174 Therefore, the test sample should be tested by connecting only electric circuits as in the existing

175 MIT folding method. The failure time of the test sample should be measured separately using a

176 visual light on the planar waveguide circuits. In addition, these tests should be measured in the

177 process of replacing the holding jig.The test sample shall be clamped by the folding jig within the

178 main controller as shown in Figure 2.
179

180 a) Photograph diagram of the folding jig b) Photograph of a folding jig and test sample

181 Figure 2 – Overview of the folding jig
182 4.2 MIT tester for flexibility test of FOECBs
183 4.2.1 FOECBs test sample of fibre optical types

184 The MIT test system for fibre optical circuits should be configured to stop the folding action of the

185 test sample if any damage starts to appear in its optical and electrical sections. Therefore, the MIT

186 test system shall be composed of an optic-electric signal control source (hereafter referred as O-E

187 signal control source), test sample, and main controller, as shown in Figure 3.

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188

189 Figure 3 – Schematic diagram of the MIT test system for fibre optical circuits

190 4.2.2 FOECBs test sample of planer waveguide optical circuit types

191 The MIT tester system for planer waveguide optical circuits shall be constructed in the same form

192 as the folding flexibility test method for existing electrical circuits, as shown in Figure 4.

193

194 Figure 4 – Schematic diagram of the MIT test system for planar waveguide optical circuits

195 4.3 O-E signal control source

196 An O-E signal control source shall be composed of a laser source, photo detector, relay switch,

197 electric power source, optical fibre, and optical connectors. The O-E signal control source supplies

198 an optical signal to the test sample, and allows the photo detector to control the relay switch based

199 on detected optical signal for on-off switching of the electric signal flow (current) within the MIT test

200 system.
201 4.4 Laser source

202 The optical output power of the laser source shall have enough larger of the minimum detected

203 power of optical detector and attenuation (optical loss) of samples. The laser source in the O-E

204 signal control source sends an optical signal to the test sample via its optical input terminal

205 connected to the protruded optical fibre. The wavelength and mode of the laser source should be

206 chosen according to the application to be used. The launching mode of the laser source should be

207 appropriate to the application of the relevant specification of O-E circuit board.

208 4.5 Photo detector

209 The minimum detected optical power of the photo detector shall be enough to detect the optical

210 power after attenuating the optical power by the test sample and light source power. The photo

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211 detector detects the optic signal flow in the test sample. The photo detector output controls the

212 relay switch inside the O-E signal control source. Therefore, the output current of the photo detector

213 should be above the minimum operating voltage of the relay switch with a proper resistance for the

214 current output. The photo detector shall have enough response frequency to detect the optical

215 power change (deviation) by the attenuation change caused by the folding distortion. At minimum,

216 the response frequency for the photo detector should be 10 times or more than the folding duration

217 (0 °to 90 °), or kHz order will be necessary.
218 4.6 Folding jig

219 The size of the jig shall be selected according to the test samples. Several types of folding jigs with

220 different bending radii are required to apply various bending tests to the test sample. Folding jigs

221 of 6 different curvature radii (1,0 mm, 2,0 mm, 3,0 mm, 4,0 mm, 5,0 mm, and 10,0 mm) should be

222 prepared (see Figure 5).
223

224 Figure 5 – MIT folding jigs (from the left, folding radius r is 1,0 mm, 2,0 mm, 3,0 mm,

225 4,0 mm, 5,0 mm and 10,0 mm)
226 4.7 Relay switch

227 The switching time shall be at least one tenth of the folding speed. The relay switch plays a role of

228 direct on-off switching control of the electric circuit in the MIT test system. That is, once the photo

229 detector detects the optic signal flow in the test sample, the relay switch stays in the on-state. If

230 the photo detector fails to detect the optic signal flow in the test sample, the relay switch turns to

231 the off-state. The relay switch operates the MIT test system depending on the detected optical

232 signal output at the photo detector, which is subject to the physical state of the test sample (e.g.,

233 either broken or non-broken state of the optic circuit).
234 4.8 Main controller

235 The main controller shall control the electrical current to fold the folding jig with enough accuracy

236 to test. The main controller supplies an electric current to the test sample and mechanically controls

237 the folding action of the test sample. The main controller may consist of the main controller and the

238 mechanical control means of folding, separately. Generally, the main controller emits the electric

239 signal by itself to perform the mechanical folding operation on the test sample. The typical electric

240 current flowing through the main controller ranges from 1 mA to 10 mA
241 5 Test sample
242 5.1 FOECB test samples of optical fibre-types

243 Test samples of optical fibre-types shall have a pigtailed shape (see Figure 6). The optical fibres

244 used in the test samples may be single-mode and/or multimode fibres. Depending on applications,

245 glass optical fibres, polymer optical fibres, and specialty optical fibres may be used to form the

246 optical circuits.

247 The optical circuits shall be positioned at a central part of the entire FOECB test samples. The

248 electrical circuits shall be positioned at peripheral areas of the optical circuit in a symmetrical

249 structure. The symmetrical structure shall have superior characteristics in size stability from the

250 viewpoint of design and reliability for the FOECB test samples, as shown in Figure 6.

251 The test samples of the optical fibre-types shall have a protruded structure with a length of l9 at

252 one side. The protruded length (l ) shall be maintained with sufficient length over 100 mm for easy

253 connection with other fibres (e.g., fibre fusion splicing). The other side of the test samples shall

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254 have a continuous fibre bending area over a 6-mm diameter with a non-end state as shown in

255 Figure 6. The bending state over the 6-mm diameter for glass optical fibres shall be maintained to

256 minimize their optical bending loss.

257 A detail requirement for structure of FOECB test samples of optical fibre-types is described in

258 Annex A

259 A position mark shall be assigned on the test sample for locating the folding position with a clamp

260 of the MIT test system.

261 The size of the test samples should be confirmed in accordance with the MIT folding jigs (see 4.6).

262 As illustrated in Figure 6, the nominal dimensions of the total length (l ) of the test sample shall be

263 130 mm within 10 % tolerance, and the nominal dimensions of the width (l ) of the test sample shall

264 be 2,5 mm to 50 mm within 10 % tolerance. It is recommended that the length (l ) of the test

265 samples from its one edge to the clamp position mark and the length (l ) from the clamp position

266 mark of the bending area to the other edge are chosen to be 100 mm and 30 mm, respectively. The

267 bending diameter (l ) of the optical circuit, spacing (l ) between two optical circuit lines, and the

4 8

268 number of optical circuits shall be decided in accordance with the user’s requirements. The pattern

269 width (l ) of the electrical circuit lines also shall be decided in accordance with the user’s

270 requirements. The thickness (l ) of the FOECB test samples is very critical because it influences

271 the minimum mechanical folding radius r. The thickness of the test sample shall be from 150 μm to

272 500 μm for the FOECB test samples of the general glass fibres defined in IEC 60793-2 series with

273 polymer over-clad protection. The thickness of the test samples should be same as that for products.

274 If there are any differences, the thickness of the test samples shall be decided in accordance with

275 the user’s requirements.
276
277 Key
278 1 electric circuit
279 2 optic circuit
280 3 position mark for clamp (folding)
281 a side view of test sample
282 b top view of test sample
283 Figure 6 – Schematic diagram of FOECB test samples of optical fibre-types
284 5.2 FOECB test samples of planar optical waveguide-types

285 The optical circuits shall be positioned at a central part of the entire FOECB test samples. The

286 electrical circuits shall be positioned at a peripheral area of the optical circuit in a symmetrical

287 structure. The symmetrical structure shall have superior characteristics in size stability from the

288 viewpoint of design and reliability for the FOECB test samples as shown in Figure 7.

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289 The test samples of the planar optical waveguide-types shall have a non-protruded structure at

290 both side (see Figure 7). The number of optical circuit lines shall be at least three for crosstalk

291 testing.

292 A requirement for structure of FOECB test samples of planar optical waveguide-types is described

293 in Annex B

294 A position mark shall be assigned on the test sample for locating the folding position with a clamp

295 of the MIT test system.

296 The size of the test samples should be confirmed in accordance with the MIT folding jigs (see 4.6).

297 As illustrated in Figure 7, the nominal dimensions of the total length (l ) of the test sample shall be

298 130 mm within 10 % tolerance, and the nominal dimensions of the width (l ) of the test sample shall

299 be 2,5 mm to 50 mm within 10 % tolerance. It is recommended that the length (l2) of test samples

300 from its one edge to the clamp position mark are chosen to be 100 mm. The optical circuits shall

301 be composed of over three optical waveguides. The spacing (l8) between two optical waveguides

302 shall be decided in accordance with the user’s requirements. The pattern width (l7) of the electrical

303 circuit lines also shall be decided in accordance with the user’s requirements. The thickness (l6) of

304 the FOECB test sample is very critical because it influences the minimum mechanical folding radius

305 r. The thickness of test samples shall be from 50 µm to 1 000 µm for FOECB test samples of the

306 planar optical waveguide-types. The thickness of the test samples should be same as that for

307 products. If there are any differences, the thickness of the test samples shall be decided in

308 accordance with the user’s requirements.
309
310 Key
311 1 electric circuit
312 2 optic circuit
313 3 position mark for clamp (folding)
314 a side view of test sample
315 b top view of
...