Study of LTCC-based pressure sensors in water

Glass-containing ceramics can be susceptible to stress corrosion in the presence of humidity. Furthermore, static loading in such conditions may adversely affect their flexural strength. Such degradation can critically affect the reliability of functional ceramic systems operating under mechanical loads. This experimental study examines the operation of pressure sensors made from low temperature cofired ceramics (LTCC). The sensors were subjected to a cyclic pressure loading in deionized water. The effect of this accelerated ageing was evaluated by comparing the changes in the offset voltage and the burst pressure to the characteristics of the sensors aged/loaded under normal ambient conditions. The results showed a satisfactory long-term stability of the sensors after one million full-scale (FS) pressure cycles as well as the sensors subjected to 10,000 overload pressure cycles (5× FS). As expected, the presence of water slightly reduces the burst pressure, but does not critically degrade the performance of the sensors or their reliability.