Multilayer ceramic capacitors with silver / palladium (Ag / Pd) terminations, from Knowles Syfer, have often been used in medical applications where non-magnetic components are required, for example, in MRI / NMR equipment. The use of conventional nickel barrier terminations is not suitable due to nickel exhibiting magnetic properties. However, RoHS requirements have dictated the use of lead-free solders, and the composition of these solders has resulted in an increase in soldering temperatures. This has caused solder leaching problems for the Ag / Pd termination, and meant alternative terminations have had to be found. As copper is non-magnetic, one solution is to use a copper barrier instead of a nickel barrier, with a tin finish on top, and this is the solution Syfer has developed. This non-magnetic termination is offered with selected non-magnetic C0G / NP0, high Q, and X7R dielectrics, providing a fully non-magnetic component (µr = 1.0000).

Recently low passive intermodulation (PIM) has become a concern in RF power amplifiers and filters, particularly the multi-carrier, higher-power variety used for cellular and other infrastructure applications. It has been stated that one of the three major causes of PIM in passive devices is components made with, or plated with, materials that exhibit some level of hysteresis, for example, nickel, iron, and more. The nickel barrier material could affect intermodulation distortion when multiple carrier frequencies share the same signal path.

To meet high-temperature 260°C soldering reflow profiles, as detailed in J-STD-020, C0G / NP0 dielectrics are supplied with FlexiCap™ or sintered termination and X7R dielectrics are supplied with Syfer’s award winning FlexiCap termination.