Vielschicht-Multipol

Multipole technology is used generally for charged particle optics which includes separating, focusing, or collimating "charged particles" (i.e., ions, electrons, etc.). A primary application of multipole technology is mass filters and particularly quadrupole mass filters. A quadrupole mass filter has a quadrupole substrate having four poles, each having a generally hyperbolic cross section, and interconnected by bridges. The bridges have apertures that facilitate the construction of poles inside the quadrupole substrate and prevent the build-up of unwanted charge. A plating substrate for electroplating is bonded to each pole substrate with a thin-film adhesion layer. Poles are electroplated upon these plating substrates. A diffusion barrier layer prevents the portions of the plating substrates from migrating to the quadrupole substrate where they would undermine the thin-film adhesion layer. Additionally, the diffusion barrier layer prevents portions of the thin-film adhesion layer from migrating away from the quadrupole substrate that could result in adhesion problems and contamination of the poles. Quadrupole mass filters formed with metallization and electroplating techniques have the advantages of consistent and predictable performance, high durability, nearly uniform thickness, and nearly hyperbolic cross-section that results in electric fields with a nearly idealized hyperbolic cross section.