A system-on-package module by fully embedding chip components in organic substrate

This paper presents a module for Wi-Fi by using system-on-package (SoP) technology. This module is composed of a single-pole-double-throw (SPDT) IC, a power amplifier module (PAM), a Tx low-pass-filter (LPF), a matching stage for a PAM, a Rx band-pass-filter (BPF), and decoupling capacitors to reject DC bias noise. All components are fully embedded in organic substrate in order to implement a slim module. A LPF and a BPF are designed and fabricated by employing chip inductors and chip capacitors. Proto-types of a BPF and a LPF are designed and verified on teflon substrate, and then these are embedded in organic substrate. A PAM and a SPDT IC as active ICs demands bypass capacitors and decoupling capacitors. All passive components have 0.3 mm thickness owing to 0.6 mm × 0.3 mm × 0.3 mm (0603) type and all active components are given as 0.5mm thickness. Organic substrate consists of epoxy and Ajimoto-bonding film (ABF). All components as active ICs and chip capacitors are fully embedded in this substrate. At first, each block is designed and fabricated on the surface of teflon substrate. Each block is embedded in organic substrate after testing. Finally, a fully embedded SoP module is simulated and implemented. The size of implemented module is given as 7.0 mm × 9.0 mm × 0.65 mm. In case of measurement for a BPF, insertion loss is less than 1.6 dB and return loss is more than 16.0 dB in pass band. In case of Tx, insertion loss is less than 0.45 dB and the return loss is more than 23.3 dB. A Tx path which includes a LPF, SPDT IC, and PAM is measured. The measured adjacent-channel ratios (ACPRs) at first and second side-lobe are -34.3 dBc and -55.1 dBc, respectively. Gain and PldB are 24 dB and 23 dBm, respectively.