Assembly challenges and demonstrations of ultra-large Antenna in Package for Automotive Radar applications

Abstract

Antenna-in-package (AiP) technology is a packaging solution where antennas are incorporated into an integrated circuit (IC) package with a RF chip [1], [2]. One of the promising technology is the Fan-out wafer level technology especially for its excellent RF performance in mobile and automotive applications [3], [4].This paper demonstrates a double FOWLP based AiP package for 77 GHz automotive radar applications with package attachment to PCB board. The ultra large package size is 32 x 16 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> with 0.6mm mold thickness after singulation. The lower mold layer consists of a Monolithic microwave integrated circuit (MMIC) chip and lithography process is done to reroute chip I/O pads to the mold compound top layer. The through mold vias (TMV) are interconnect vias formed through the mold compound to connect to the M3 RDL layer. The antenna excitation elements are then fabricated onto the surface of the 2 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">nd</sup> mold EMC 2. The package is then attached to an interposer PCB and functional application board with double-side surface mount components for electrical testing and characterization. Detailed assembly process parameters on wafer reconfiguration, die placement shift compensation, compression wafer molding and debonding process to establish die placement accuracy and die protrusion of ±10um will be discussed in this work. Details of the thermocompression bonding process (TCB) for the package attachment to the PCB will also be summarized in this paper.