IEC TR 61189-5-506:2019

IEC TR 61189-5-506 ®
Edition 1.0 2019-06
TECHNICAL
REPORT
colour
inside
Test methods for electrical materials, printed boards and other interconnection
structures and assemblies –
Part 5-506: General test methods for materials and assemblies – An
intercomparison evaluation to implement the use of fine-pitch test structures for
surface insulation resistance (SIR) testing of solder fluxes in accordance with
IEC 61189-5-501
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IEC TR 61189-5-506 ®
Edition 1.0 2019-06
TECHNICAL
REPORT
colour
inside
Test methods for electrical materials, printed boards and other interconnection

structures and assemblies –
Part 5-506: General test methods for materials and assemblies – An

intercomparison evaluation to implement the use of fine-pitch test structures for

surface insulation resistance (SIR) testing of solder fluxes in accordance with

IEC 61189-5-501
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 31.180 ISBN 978-2-8322-7083-7

– 2 – IEC TR 61189-5-506:2019 © IEC 2019
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 7
4 Test board concept for intercomparison . 7
4.1 The need for a fine-pitch SIR pattern . 7
4.2 Test board design . 8
4.3 Test board fluxing . 9
5 Test procedure for intercomparison . 10
5.1 Sample preparation . 10
5.2 Preparation of samples for humidity chamber . 11
5.3 Placement of samples inside the humidity chamber . 11
5.4 Resistance measurements . 12
5.5 Evaluation of results . 12
5.6 Additional information . 12
6 Results . 12
Bibliography . 23

Figure 1 – TB144 . 9
Figure 2 – Connector arrangement . 11
Figure 3 – Sample orientation in test chamber . 12
Figure 4 – Participants (a to f) resistance measurements for the six test patterns on
the checker board . 13
Figure 5 – Participant A control boards . 13
Figure 6 – Participant A flux loaded boards . 14
Figure 7 – Participant B control boards . 14
Figure 8 – Participant B flux loaded boards . 14
Figure 9 – Participant C control boards . 15
Figure 10 – Participant C flux loaded boards . 15
Figure 11 – Participant D control boards . 15
Figure 12 – Participant D flux loaded boards . 16
Figure 13 – Participant E control boards . 16
Figure 14 – Participant E flux loaded boards . 16
Figure 15 – Participant F control boards . 17
Figure 16 – Participant F flux loaded boards . 17
Figure 17 – Participant G control boards . 17
Figure 18 – Participant G flux loaded boards . 18
Figure 19 – Participant D, and evidence of a fibre and the effect on the SIR . 18
Figure 20 – Participant E and evidence or corrosion shorting across the gap . 18
Figure 21 – Participant G and evidence of a water droplet and the resulting drop in
SIR and dendrite like failure . 19
Figure 22 – Participant G and a corrosion defect probably from a flux residue . 19

Figure 23 – Participant C dendrites and corrosions formed on all SIR patterns of all
fluxed samples tested at 85°C/85% . 19
Figure 24 – The average final SIR value for the control boards . 20
Figure 25 – The average final SIR value for the flux loaded boards . 20
Figure 26 – The average final SIR for flux-loaded patterns by participant . 21
Figure 27 – Final SIR plotted as ohm.squares . 21
Figure 28 – Ratio of the log Ω.square value to the 500-µm pattern . 22

Table 1 – SIR pattern information . 9
Table 2 – Flux to be used for SIR evaluation test . 10
Table 3 – Samples for SIR evaluation testing . 10

– 4 – IEC TR 61189-5-506:2019 © IEC 2019
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
TEST METHODS FOR ELECTRICAL MATERIALS, PRINTED BOARDS AND
OTHER INTERCONNECTION STRUCTURES AND ASSEMBLIES –

Part 5-506: General test methods for materials and assemblies – An
intercomparison evaluation to implement the use of fine-pitch test
structures for surface insulation resistance (SIR) testing of solder fluxes
in accordance with IEC 61189-5-501

FOREWORD
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data of a different kind from that which is normally published as an International Standard, for
example "state of the art".
IEC/TR 61189-5-506, which is a technical report, has been prepared by IEC technical
committee 91: Electronics assembly technology.

The text of this Technical Report is based on the following documents:
Draft TR Report on voting
91/1500/DTR 91/1530A/RVDTR
Full information on the voting for the approval of this Technical Report can be found in the
report on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
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