Glass-Based IC-Embedded Antenna-Integrated Packages for 28-GHz High-Speed Data Communications

Chip-embedded mm-wave antenna-integrated modules are demonstrated, for the first time, on panel-scale ultra-thin glass substrates, for high-speed 5G communication standards in the n257 band (26.5 – 29.5 GHz) defined by 3GPP. Co-packaging of amplifiers, filters, and antennas with minimal package parasitics is the key to realize mm-wave package systems. Parasitics arise from on-package and chip-to-package interconnects. This paper focuses on reduced chip-to-package losses and implementation of filters and antennas with chip-embedding structures in glass substrates. To demonstrate the benefits of glass-panel embedding (GPE) for 5G communications, the interconnect losses are benchmarked with the C4-bump based flip-chip technique. The electrical performance shows that the chip-embedding structure with a glass substrate lead to 3X lower insertion loss from chip to antenna than the flip-chip assembly method with C4 bumps. This reduced chip-to-antenna insertion loss brings about the enhanced efficiency and gain of the patch antennas integrated on top of the glass substrates. The process development and electrical performance are benchmarked with emerging 5G substrate technologies such as fan-out wafer level packaging.

I. INTRODUCTION

Fifth-generation (5G) communication technology addresses three categories of communication services: enhanced mobile broadband (eMBB), massive machine-type communication (mMTC), and ultra-reliable low-latency communication (URLLC). This set of trends for high-speed wireless communications has been driving 5G to utilize various frequency spectra, where the frequency range lower than 3 GHz is preferred for mMTC, and sub-6 GHz and several millimeter-wave (mm-wave) frequency spectra are selected for eMBB and URLLC [1]. Heterogeneous integration of elements and components in the mm-wave frequencies is one of the key technologies to enable the aforementioned communication services. The elements and components in front-end modules at mm-wave frequency spectra include signal interconnects [2], power management, antenna array in package [3], [4], [5], beam-forming integrated circuits (ICs), monolithic microwave integrated circuits (MMICs), filters [6], power dividers [7], and other active and passive components.