Abstract
Electrically conductive adhesives (ECAs) are starting to replace metallic solders in recent designs of photovoltaic (PV) modules. This transition represents a significant material change, and a proper understanding of the durability and reliability of the new interconnect needs to be established. This paper presents our continued work on developing a degradation model for ECA interconnects in PV modules. Here, we characterize the fracture mechanics properties of an epoxy-based ECA, for both critical and subcritical, mode I and mode II loading conditions. Emphasis is on the influence of different environmental conditions such as temperature and humidity. We use the Finite Element Method to account for residual stresses, induced by temperature changes and moisture absorption, and correct the apparent fracture toughness. We found that high moisture levels not only can weaken the fracture resistance of the ECA interconnect, but can also promote subcritical debonding at significantly lower driving forces than in dry environments.
Original language | American English |
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Article number | 107398 |
Number of pages | 20 |
Journal | Engineering Fracture Mechanics |
Volume | 241 |
DOIs | |
State | Published - 2021 |
Bibliographical note
Publisher Copyright:© 2020
NREL Publication Number
- NREL/JA-5K00-78264
Keywords
- Electrically conductive adhesives
- Fracture properties
- Mode I
- Mode II
- Photovoltaic
- Subcritical debonding