Passive component manufacturer, Syfer Technology, has announced the availability of an innovative range of leaded non-magnetic, high voltage, chip capacitors suitable for use in MRI scanners. There is a trend in scanning equipment to increase the magnetic field in order to provide higher resolution images. As a result the importance of using non-magnetic components within such equipment has increased. Even mildly magnetic devices can affect image quality and they contribute towards increased system operating temperature, which can impact component reliability.
Syfer’s non-magnetic capacitors are designed to be used to help tune the body coils, to enable them to more effectively detect the weak magnetic signals induced in the body or limb which is being scanned.
This range of high voltage chip capacitors features ribbon leads made from silver plated copper. Leaded components allows the chip capacitor to be decoupled from the board to facilitate hand soldering and also offers improved mechanical decoupling,- while the combination of silver over copper optimises thermal characteristics and allows higher operating power. In addition, the leads are attached with high melting point solder, and are therefore suitable for use with RoHS compliant solders that reach a soldering reflow temperature of 260oC.
The chip capacitors are available in C0G/NP0, High Q and X7R dielectrics, and package sizes of 2225 and 4040. Capacitance values range from 2pF to 10nF (High Q). The working voltages of the capacitor range from 200V to 7kV, ideal for the typically high voltage and high frequency circuits found in medical equipment. To ensure high frequency performance operation, select the High Q versions for low ESR. Operating temperature range is -55ºC to 125oC, and insulation resistance is 100Gohms minimum at 100V dc or 1000s (whichever is less).
These non-magnetic components are equally as suitable for other high RF power applications in the telecom, industrial, military or space sectors, where a system might induce a magnetic field. Losses are minimised, thereby improving overall performance and improve reliability. Devices are readily available in production quantities from 12 weeks depending on type and quantity.