PURPOSE: To make it possible to measure even a constant acceleration by provid ing a substrate having a hollow part, a thermal insulation film having a cantile ver formed above the hollow part, and a thermister employing a thin film resis tor.
CONSTITUTION: The acceleration sensor 5 comprises a thermister 6 formed on a cantilever 3b. Since the cantilever 3b is formed above the hollow part 2a of a substrate 2, it is thermally insulated from the substrate 2 and the heat flows directly from the thermister 6 to a stem 7 through a medium of air or the like. When the mean free path L of gas molecules present in the hollow part 2a and the difference of dimension (d) between the thermal insulation film 3 and the stem 7 satisfy a relationship Ld, the heat quantity Q being transferred from the thermister 6 to the stem 7 can be represented by a formula Q=KA(T2-T1)/d, and the heat quantity Q varies significantly as the dimension (d) varies. In the formula, K: thermal conductivity, A: area of the thermal insulation film 3 for forming the thermister 6, TA: temperature of thermister 6, and T2: temperature of stem 7. The acceleration is calculated based on the flexure of the cantilever 3b.
TOMONARI SHIGEAKI
MATSUSHIMA CHOMEI
