Obsolescent Polycarbonate Capacitors
Ex-stock availability of MFD, Advance and MPE polycarbonate capacitors, including the M2B series with CECC release. Call 01591 610408 or email sales@charcroft.com

Background: Polycarbonate Capacitor Obsolescence
In September 2000 Bayer AG, announced plans to withdraw from manufacturing capacitor-grade Makrofol® polycarbonate film. As the world’s sole source for this material, Bayer AG offered manufacturers of polycarbonate capacitors a last-time-buy of the raw material. There is now evidence that the supply of polycarbonate capacitors is beginning to tighten and prices beginning to rise.

Replacing Polycarbonate Capacitors
The most common suggested alternatives to polycarbonate (PC) are polypropylene (PP) and polyphenylene sulphide (PPS) although polyester (PET) may be suitable for capacitance tolerances of 5% and above. Polyphenylene sulphide provides performance characteristics which are closest to polycarbonate film but it is also subject to the risks associated with using sole-sourced raw materials. Designers therefore may wish to consider polypropylene film which has a lower dissipation factor across the entire temperature range. For higher tolerance applications, polyester film, which matches the capacitance stability of polycarbonate over time but not over changes in temperature, may be suitable.