RF Inductors Integrated in Organic Packaging

This paper presents RF inductors implemented in multilayer organic packaging substrates. The embedded inductors are designed using a 6 metal layer organic substrate based on a 2 build-up layers - 1 core layer - 2 build-up layers stack. The core and build-up layer materials have very low loss tangent at GHz frequencies and their thickness is chosen to assess two types of inductor structures: spiral and solenoid. The designed inductors present high quality factor with low foot print e.g. inductance of 7 nH with a 0.36 mm
²
footprint, a maximum quality factor of 28 at 1.5 GHz and a 5.8 GHz self-resonant frequency. Several inductors with different dimensions are presented and compared to both state of the art organic inductors and commercial inductors in term of electrical performances and footprint.