CALIBRATION-LESS MICRO-FABRICATED VACUUM GAUGE DEVICES AND METHOD FOR MEASURING PRESSURE

摘要

A manner to determine pressure (e.g. inside a vacuum package, such as a MEMS die), without prior calibration, is provided using a model and a set of one or more gauges (e.g. Pirani, thermistor, thermocouple gauges) with distinct geometries. In order to calculate pressure from the electrical measurements performed on the gauges, there are several intermediate steps and an analytical model describes each of these steps. Besides the electrical measurements, other inputs are required, such as material properties and certain dimensions, which may not be known accurately. Several different gauge geometries are proposed which can be combined in order to determine the vacuum (pressure) level without knowing the values of these inputs beforehand.