Integration of precision passive components on silicon for performance improvements and miniaturization

We present a silicon technology that allows integration of precision passive components such as high density 3D-capacitors, resistors, and inductors with various diodes and zener devices. We couple this hyper-integration of passives in silicon with WLCSP packaging to design compact, high performance devices suitable for space constrained wireless and personal electronics applications. We demonstrate the application of this technology for designing a protection/filter IC for cellular microphone. The IC provides audio and RF filtering along with ESD protection compliant with IEC61000-4-2 specifications. All necessary components including the biasing network, high density capacitors (30 nF/mm2), diodes, and resistors are included on the chip. Packaged as a 1.2 mmtimes1.2 mm WLCSP device, and with all the integrated passive components, a high level of miniaturization is achieved.