Note: Inhibiting bottleneck corrosion in electrical calcium tests for ultra-barrier measurements

作者：Nehm F^*; Mueller Meskamp L; Klumbies H; Leo K

来源：Review of Scientific Instruments, 2015, 86(12): 126110.

DOI：10.1063/1.4938540

A major failure mechanism is identified in electrical calcium corrosion tests for quality assessment of high-end application moisture barriers. Accelerated calcium corrosion is found at the calcium/electrode junction, leading to an electrical bottleneck. This causes test failure not related to overall calcium loss. The likely cause is a difference in electrochemical potential between the aluminum electrodes and the calcium sensor, resulting in a corrosion element. As a solution, a thin, full-area copper layer is introduced below the calcium, shifting the corrosion element to the calcium/copper junction and inhibiting bottleneck degradation. Using the copper layer improves the level of sensitivity for the water vapor transmission rate (WVTR) by over one order of magnitude. Thin-film encapsulated samples with 20 nm of atomic layer deposited alumina barriers this way exhibit WVTRs of 6 x 10(-5) g(H2O)/m(2)/d at 38 degrees C, 90% relative humidity.

• 出版日期2015-12