Giving design engineers a new option for reducing the size of portable electronic devices, AVX recently developed the industry’s first 0402 tantalum chip capacitor. Designated the 0402 TACMicrochip® Series, the capacitors offer the highest volumetric efficiency currently available, delivering up to 10µF in an 0402 case size, with superior leakage characteristics. TAC 0402 tantalum chip capacitors are ideal for applications that require high capacitance values along with low leakage, such as in battery-powered equipment, as well as medical applications such as heart pacemakers.
The unique construction of the TACMicrochip® Series devices eliminates the welded lead frame common in conventional molded tantalum capacitor devices, which dramatically increases the space available for the active tantalum element even as the package itself becomes smaller. This reduction in the package size enables designers to add higher capacitance value parts to existing circuits; or to use smaller package sizes to further miniaturize their circuits.
Applying semiconductor manufacturing techniques to replace the less efficient lead frame methods enabled AVX to achieve the dramatic reduction in package size. By depositing capacitor material directly on a tantalum wafer substrate, the devices can be built up in a series of automated process steps, and the resulting wafer can be sliced into individual chips like semiconductor die.
Typical specifications for the 0402 TACMicrochip® Series include some of the industry’s highest CV values for 0402 devices, such as 10µF@2V; 4.7µF@4V; 2.2µF@6.3V; and 1.0µF@10V; with maximum ESR values of 15Ω (@100KHz).
Like most AVX components, the TACMicrochip Series is offered in a lead-free version, and features AVX’s “soft termination” technology that compensates for the thermal mismatch between components and PC boards – which can often cause solder joint failure in these devices.
One of the key benefits of tantalum technology is capacitance stability over temperature. While ceramic products typically offer just half the capacitance across the temperature range due to the high K dielectrics used, the TACmicrochip® 0402 devices have a stable capacitance range from -55° to +125°C. As with all tantalum devices, TACmicrochip® capacitors are not subject to piezo effects that can result in electrical noise. AVX’s TACmicrochip® Series are also available in 0603, 0805 and 1206, or standard L, R and A case sizes as well as the 0402 (K case size).