Hence other frequencies has been utilized as an alternative with the use of HP4194A. This device was next exposed
to an ambient humidity of 30–60% RH and had a sensitivity
of 3.5 pF/%RH (at 50 kHz) and 3.8 pF/%RH (at 10 kHz)
as illustrated in Fig. 13. These results indicate that the sensor
can be readily utilized to monitor the environment inside anodically
bonded packages. Future efforts will focus on integration
of the RH sensor into the packaging substrate fabrication
process and performing long term in vivo and in vitro package
reliability tests.