IEC 63251:2023

Test method for mechanical properties of flexible opto-electric circuit boards under thermal stress

IEC 63251:2023 defines the thermal endurance test methods for reliability assessment of flexible opto-electric circuit boards. The purpose of this document is to accommodate the uniform thermal characteristics required by the flexible opto-electric circuit in high temperature environments such as automobiles. In particular, this document specifies a test method to inspect the occurrence of colour exchange, deformation and delamination of flexible opto-electric circuit boards under thermal stress.

Méthode d’essai des propriétés mécaniques des circuits optoélectriques souples sous contrainte thermique

L'IEC 63251:2023 définit les méthodes d’essai d’endurance thermique relatives à l’évaluation de la fiabilité des circuits optoélectriques souples. Le présent document a pour objet de tenir compte des caractéristiques thermiques uniformes exigées par le circuit optoélectrique souple dans les environnements à haute température comme les automobiles. Le présent document spécifie notamment une méthode d’essai pour déceler l’apparition d’un changement de couleur, d’une déformation et d’une déstratification des circuits optoélectriques souples sous contrainte thermique.

General Information

• Status: Published
• Publication Date: 31-Oct-2023
• ICS: 31.180 - Printed circuits and boards
• Technical Committee: TC 91 - Electronics assembly technology
• Drafting Committee: WG 10 - TC 91/WG 10
• Current Stage: PPUB - Publication issued
• Start Date: 01-Dec-2023
• Completion Date: 01-Nov-2023

Standards Content (Sample)

IEC 63251 ®
Edition 1.0 2023-11
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Test method for mechanical properties of flexible opto-electric circuit boards
under thermal stress
Méthode d’essai des propriétés mécaniques des circuits optoélectriques
souples sous contrainte thermique

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IEC 63251 ®
Edition 1.0 2023-11
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Test method for mechanical properties of flexible opto-electric circuit boards

under thermal stress
Méthode d’essai des propriétés mécaniques des circuits optoélectriques

souples sous contrainte thermique

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 31.180  ISBN 978-2-8322-7750-8

– 2 – IEC 63251:2023 © IEC 2023
CONTENTS
FOREWORD . 4
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Test method . 7
4.1 General . 7
4.2 Test sample . 7
4.3 Test process . 8
4.3.1 General description of the test . 8
4.3.2 Preconditioning . 9
4.3.3 Test . 9
4.3.4 Recovery . 9
4.3.5 Final measurements . 10
5 Report . 10
Annex A (informative)  Example of optical bending loss test results with general glass
optic fibres . 11
Annex B (informative) Example of preparation method of O-E circuit test samples
(optic fibre type) . 12
B.1 General . 12
B.2 Manufacturing processes of the FOECBs with optic fibres (POF, GOF) . 12
B.3 Manufacturing processes of the FOECBs with optical polymer waveguides . 13
B.4 Characteristics of the optic fibres . 14
Annex C (informative) Example of reflow assembly simulation test results . 15
C.1 General . 15
C.2 Results of reflow assembly simulation test for a LED chip mounted FOECB
with GOF . 15
C.3 Results of reflow assembly simulation test for a transparent FOECB with
GOF for display applications . 16
C.4 Results of reflow assembly simulation test for a polyimide (PI) based FOECB
with GOF . 16
C.5 Results of reflow assembly simulation test for a polymer-based FOECB . 17
Annex D (informative) Example of thermal shock endurance test results . 18
D.1 General . 18
D.2 Results of thermal shock endurance test for an FOECB with GOF . 18
Annex E (informative) Example of humidity storage test results . 19
E.1 General . 19
E.2 Results of humidity storage test for an FOECB with GOF . 19
E.3 Results of humidity storage test for an FOECB with POF . 19
Bibliography . 21

Figure 1 – Schematic diagram of FOECB (top view) . 7
Figure 2 – Schematic diagrams of the FOECB test samples of fibre type . 8
Figure 3 – Schematic diagram of the FOECB test samples of fibre type . 8
Figure A.1 – Bending loss test setup . 11
Figure A.2 – Optical loss versus bending diameter . 11
Figure B.1 – Arrayed structure of the FOECB test samples formed on one sheet . 12

Figure B.2 – Fabrication of the optic circuits with optic fibres . 13
Figure B.3 – Fabrication of the optic circuits with optic polymer waveguide via the
photo-etching method . 13
Figure C.1 – LED chip mounted FOECB. 15
Figure C.2 – Appearance of a LED chip mounted FOECB after the reflow assembly

simulation test . 15
Figure C.3 – Appearance of a transparent FOECB with GOFs after the reflow assembly
simulation test . 16
Figure C.4 – Appearance of a PI based FOECB with GOF after the reflow assembly
simulation test . 16
Figure C.5 – Appearance of a polymer-based FOECB after the reflow assembly

simulation test . 17
Figure D.1 – Appearance of an FOECB with GOF after the thermal shock test . 18
Figure E.1 – Appearance of an FOECB with GOF after the humidity storage test . 19
Figure E.2 – Appearance of an FOECB with POF after the humidity storage test . 20

Table 1 – Thermal endurance test class for FOECB . 9

– 4 – IEC 63251:2023 © IEC 2023
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
TEST METHOD FOR MECHANICAL PROPERTIES OF FLEXIBLE
OPTO-ELECTRIC CIRCUIT BOARDS UNDER THERMAL STRESS

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