RF Characterization in Range of 18GHz in Fan-out Package Structure Molded by Epoxy Molding Compound with EMI Shielding Property

Abstract

In recent years’ fan-out package is playing a most important role in heterogeneous integrated system in package (SiP) technology because of improved degree of freedom of design by using fan-out area of package. The fan-out package is now used as central processing unit (CPU), graphics processing unit (GPU), high bandwidth memory (HBM), mobile application processor (AP), audio codec, antenna in package (AiP) and so on. We fabricated the EMC with Electromagnetic interference (EMI) shielding properties using EMI shielding filler to fabricate the antenna directly on the surface of EMC to reduce the thickness and interconnection of AiP. AlN and carbonyl-Fe was applied to ceramic filler and EMI shielding filler of granular-type EMC, respectively. With increasing contents of carbonyl-Fe, the coefficient of thermal expansion (CTE) of EMC increased and modulus of EMC decreased. Relative permittivity of EMC increased with increasing contents of carbonyl-Fe following the percolation theory. The near-field shielding effectiveness of EMC consisted of 25% carbonyl-Fe was more than 10dB at the frequency range of 0.8 kHz to 18 GHz. The shielding effectiveness of EMC with Fe was mainly contributed by shielding by absorption. The dielectric loss of transmission that evaluated using CPW increased with increasing Fe contents of EMC because of relative permittivity.