An empirical model to describe performance degradation for warranty abuse detection in portable electronics
针对便携式电子产品中液体损伤指示器（LDI）可靠性存疑的问题，设计了寿命测试方案并提出了基于物理机制的退化模型，通过智能手机热循环实验验证，可快速准确评估LDI性能。
Portable electronics makers have introduced liquid damage indicators (LDIs) into their products to detect warranty abuse caused by water damage. However, under certain conditions, these indicators can exhibit inconsistencies in detecting liquid damage. This study is motivated by the fact that the reliability of LDIs in portable electronics is suspected. In this paper, first, the scheme of life tests is devised for LDIs in conjunction with a robust color classification rule. Second, a degradation model is proposed by considering the two physical mechanisms—(1) phase change from vapor to water and (2) water transport in the porous paper—for LDIs. Finally, the degradation model is validated with additional tests using actual smartphone sets subjected to the thermal cycling of −15 °C to 25 °C and the relative humidity of 95%. By employing the innovative life testing scheme and the novel performance degradation model, it is expected that the performance of LDIs for a particular application can be assessed quickly and accurately.