Murata has developed a series of MLCCs with an external metal terminal design which is claimed to reduce problems associated with mounting larger size MLCCs, including acoustic noise production and cracks caused by flexing the PCB. The KRM series design allows two capacitors to be mounted on top of each other, thus achieving high capacitance values inside small footprints, claims the company. The capacitors feature ferric alloy terminals, which lift the body of the capacitor up to 1mm above the surface of the PCB when mounted. This is claimed to ensure that bending forces are not transmitted between the PCB and the capacitor and vice versa. The capacitors, when mounted on a PCB and subjected to DC 20V, AC 1V-p-p, produced 20dB of acoustic noise, and when subjected to up to 6mm of PCB flexing, no cracks appeared. In heat shock cycle tests, after 2000 cycles of -55 to +125°C, 5min, there was no visible cracking or deformation of the capacitor or the solder joints, claims the company. The series ranges from the KRM55WR71E476MH01K, a 47µF part measuring 6.1x5.3x6.4mm and rated at 25V, to the KRM55TR72A106MH01K, a 10µF part rated at 100V which measures 6.1x5.3x4.8mm.
