Non-Magnetic Surface Mount And Ribbon Leaded MLC Capacitors
The use of a copper barrier instead of a nickel barrier, with a tin finish on top, is the solution Knowles Precision Services has developed for non-magnetic applications.
MLC capacitors with silver/palladium (Ag/Pd) terminations have often been used in medical applications where non-magnetic components are required, for example in MRI equipment - however, conventional nickel barrier terminations are not suitable due to their magnetic properties. In addition, RoHS requirement to use lead-free solders would cause an increase in soldering temperatures and cause solder leaching problems for the Ag/Pd termination.
This has meant alternatives have had to be found and one solution is to use a copper barrier instead of a nickel barrier, with a tin finish on top. 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). For full product details, download the datasheet.