IEC TR 63141:2020

Damp heat, steady state (unsaturated pressurized vapour with air)

IEC TR 63141:2020(E) describes a new test method to control the volume of air injected into a conventional HAST chamber filled with water vapour. This document provides an overview of the conventional HAST chamber, an overview of the air-HAST equipment where air is incorporated into the HAST chamber, an example of an air-HAST test apparatus, and application examples of air-HAST.

General Information

• Status: Published
• Publication Date: 08-Apr-2020
• ICS: 01 - GENERALITIES. TERMINOLOGY. STANDARDIZATION. DOCUMENTATION
• ICS: 19.040 - Environmental testing
• Technical Committee: TC 104 - Environmental conditions, classification and methods of test
• Drafting Committee: PT 63141 - TC 104/PT 63141
• Current Stage: PPUB - Publication issued
• Completion Date: 09-Apr-2020

Standards Content (Sample)

IEC TR 63141 ®
Edition 1.0 2020-04
TECHNICAL
REPORT
colour
inside
Damp heat, steady state (unsaturated pressurized vapour with air)

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IEC TR 63141 ®
Edition 1.0 2020-04
TECHNICAL
REPORT
colour
inside
Damp heat, steady state (unsaturated pressurized vapour with air)

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 19.040 ISBN 978-2-8322-8090-4

– 2 – IEC TR 63141:2020 © IEC 2020
CONTENTS
FOREWORD . 5
INTRODUCTION . 7
1 Scope . 8
2 Normative references . 8
3 Terms and definitions . 8
4 Overview of HAST and air-HAST . 9
4.1 Overview of HAST chamber . 9
4.1.1 Structure of HAST chamber . 9
4.1.2 Definition of humidity . 10
4.2 Structure of air-HAST equipment . 12
4.2.1 General . 12
4.2.2 Air concentration and relative humidity . 14
5 Evaluation of tin whisker growth from lead-free plating and solder-joints . 14
5.1 Whisker of lead-free solder (comb-type substrate) . 14
5.1.1 General . 14
5.1.2 Summary of evaluation results of solder-joint whisker growth [3] [4] . 15
5.1.3 Conclusion . 24
5.2 Lead-free whisker of plating (mounting substrate) . 25
5.2.1 General . 25
5.2.2 Test method . 25
5.2.3 Test results. 26
5.2.4 Observations . 27
5.2.5 Conclusion . 29
6 Applied case of JISSO using electrically-conductive adhesive and acceleration
test under humidity environments for joining parts . 29
6.1 General . 30
6.2 Experiment method . 30
6.2.1 Testing material . 30
6.2.2 Test conditions . 30
6.2.3 Measurement and evaluation method . 31
6.3 Test results . 31
6.3.1 Experimental result . 31
6.3.2 Test result (1608R/paste A) . 36
6.4 Points of attention . 38
6.5 Summary . 38
7 Applied air-HAST to c-Si PV modules evaluation tests . 39
7.1 Background and objective . 39
7.2 Photovoltaic module structure and deterioration factors . 39
7.3 Test methods . 40
7.3.1 Crystalline silicon photovoltaic module type-approval international
standard . 40
7.3.2 Air-HAST work . 41
7.3.3 Test samples . 41
7.3.4 Test conditions . 42
7.3.5 Measurement and analysis . 44
7.4 Test results . 44
7.4.1 DHT testing . 44

7.4.2 Saturated HAST. 46
7.4.3 Air-HAST . 47
7.4.4 External appearance comparison . 48
7.4.5 Use of dark I-V measurement to infer deterioration factors . 50
7.4.6 Use of ion chromatography to quantify residual acetic acid ions . 50
7.5 Discussion . 51
7.5.1 Environment test method comparisons . 51
7.5.2 Power-loss profiles by moisture permeation . 52
7.5.3 Comparisons by ion chromatography acetic acid quantification . 52
7.6 Conclusion . 53
8 Summary . 54
Bibliography . 55

Figure 1 – Two types of HAST equipment and their structures . 9
Figure 2 – Image of air vent process . 11
Figure 3 – Saturated test . 11
Figure 4 – Unsaturated test. 12
Figure 5 – Structure of two-vessel type air-HAST chamber . 13
Figure 6 – Structure of one-vessel type air-HAST chamber . 14
Figure 7 – Example of test vehicle with comb pattern . 15
Figure 8 – Process flow for sample build . 16
Figure 9 – Temperature/relative humidity profiles of HAST and air-HAST . 17
Figure 10 – Whisker generation situation in air-HAST . 19
Figure 11 – Mapping of the cross-section at the solder fillet in HAST . 20
Figure 12 – Mapping of the cross-section at the solder fillet in air-HAST . 20
Figure 13 – Arrhenius plot of the bromine-based flux . 22
Figure 14 – Reciprocal of relative humidity of whisker generation on solder . 22
Figure 15 – Humidity properties of whisker generation on solder (pt.2) . 23
Figure 16 – Evaluated sample . 25
Figure 17 – Whisker formation (Substrate: Cu) . 27
Figure 18 – Cross-section inspection results with electron-imaging (Substrate: Cu) . 28
Figure 19 – Elements analysis . 29
Figure 20 – Substrate for conductive resistance measurement and example of
component mounting . 30
Figure 21 – Humidity test conductive resistance monitor test status . 31
Figure 22 – Example of the conductive resistance value change . 32
Figure 23 – Weibull plot of temperature acceleration (under fixed humidity conditions) . 32
Figure 24 – Arrhenius plot (fixed humidity) . 33
Figure 25 – Weibull plot of humidity acceleration (under fixed temperature conditions) . 34
Figure 26 – Arrhenius plot (fixed temperature) . 35
Figure 27 – Eyring plot of all conditions . 35
Figure 28 – Comparison of paste (120 °C/85 % RH Air-HAST) . 36
Figure 29 – Cross-section analysis of 1608R after a humidity test (SEM image) . 37
Figure 30 – Magnified image of cross-section analysis of 1608R after a humidity test
(SEM image) . 37

– 4 – IEC TR 63141:2020 © IEC 2020
Figure 31 – Cross-section analysis of 1608R after a humidity test (SEM image) and
examples of componential analysis by EDX . 38
Figure 32 – Structure of c-Si PV module . 40
Figure 33 – Qualification test sequence in IEC 61215-1 [23] . 41
Figure 34 – Appearance of modules . 42
Figure 35 – EL images after DHT . 45
Figure 36 – Degradation profiles with DHT . 46
Figure 37 – EL images of HAST 105 °C/100 %
...