A micro-fabricated mounting arrangement for a quadrupole device

This invention provides a method of mounting cylindrical electrodes in the geometry of a miniature electrostatic quadrupole, which can act as a quadrupole mass filter or a quadrupole ion guide, or be used in a linear quadrupole ion trap. The electrodes 109 are mounted in pairs on microfabricated supports 101 and 102, which are formed from conducting parts on an insulating substrate 100. The supports include a suspended flexure system (see Figure 2) to relieve strains caused by mismatch between the thermal expansion coefficients of the electrodes and the substrate. Each suspended support member may have a portal frame geometry (see Figure 3). A complete quadrupole is constructed from two such supports, which are spaced apart by further conducting spacers (see Figure 4).