Effects of different combinations of environmental tests on the reliability of UHF RFID tags

Accelerated environmental tests can be used to study the effects of environmental stresses on reliability. Typically environmental tests are used in parallel so that only one test is performed for test samples and new test samples are used in another test. However, different tests one after another for the same test samples may describe the operational environment better and give more reliable results in a short time. In addition, the different stresses may accelerate the effects of another stress, and such behaviour can be perceived if combinations of environmental tests are used. In this study, passive ultra high frequency (UHF) radio frequency identification (RFID) tags were tested with different combinations of environmental tests. Some of the tags were kept first in a bending test, in a constant humidity test or in a temperature cycling test, and then subjected to a humidity cycling test. In addition, as a reference some of the tags were tested only in the humidity cycling test. Changes in the performance parameters of the RFID tags were examined during testing. The tags which were held first in the constant humidity test failed significantly faster than the other test combinations. Consequently, on the basis of this study, it is important to study the effect of sequential environmental tests on the same test samples.