1. Regulating the coefficient of thermal expansion in electrodeposited Invar alloy films for fine metal masks via vacuum and hydrogen annealing.
- Author
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Ren, Wei, Yu, Yu, Lan, Xi, Guo, Lei, and Guo, Zhancheng
- Abstract
Electrodeposited Invar alloy film is highly desirable for manufacturing fine metal masks (FMMs) used in Organic Light-Emitting Diodes (OLEDs). However, its development is limited by the high coefficient of thermal expansion (CTE). In this study, we successfully obtained a coarse-grained electrodeposited Invar alloy film with near-zero thermal expansion and inclusions smaller than 300 nm, achieved through abnormal grain growth (AGG) induced by second-phase particles. Our experiments confirmed that these second-phase particles are composed of (Fe, Ni)1-xS. During AGG, the aggregation and coarsening of these second-phase particles lead to changes in local strain energy, and the combined effects of surface and strain energies results in the rapid preferential growth of (110)-oriented grains. The matrix grains are engulfed by large-sized grains and transformed into sub-grains, which merge with the abnormally growing grains through grain rotation. An inverse relationship was found between CTE and grain size. Following vacuum annealing at 800 °C for 2 h and hydrogen annealing for 1 h, the average grain size increased to approximately 400 µm, while the CTE was reduced to 0.3 × 10–6/ °C. This study provides a new method for obtaining electrodeposited Invar alloy films that meet commercial applications criteria for and are suitable for FMM fabrication for high-definition OLEDs. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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