Fabrication and testing of a miniature cylindrical ion trap mass spectrometer constructed from low temperature co-fired ceramics

Abstract

A novel technique for the fabrication of miniature cylindrical ion trap (CIT) mass spectrometers using a non-conductive substrate has been developed. This technique demonstrated the feasibility of batch fabricating accurate and low-cost CITs. A CIT ring electrode ( r 0 = 1.375 mm) was fabricated using multiple layers of low temperature co-fired ceramics (LTCC) which were punched and then compressed in a ring-electrode die. Uniform compression was achieved, and cracking avoided, by tailoring the thickness of the LTCC stack. The stack was then fired at 850 °C to convert the LTCC into a ceramic ring. Areas to be metallized were patterned photolithographically after the ring was subjected to electroless plating. Stainless steel endplates were affixed to the ring electrode to complete the CIT. The prototype CIT was tested in the mass selective instability mode without axial modulation and produced mass spectra with a typical peak width of 1.8 m/ z. Simulations of operation were also performed in ITSIM 5.0 after SIMION 7.0 was used to calculate the contribution of higher order multipoles to the nominally quadrupole potential inside the CIT.