A Silicon-Based Fanout Technology with High Aspect Ratio TSV for RF Heterogenous Integration Applications

EasyChair Preprint 13440

Abstract

Advanced packaging technology has demonstrated its unique technical advantages in miniaturization and high-density integrated application of RF Microsystems. Among many advanced packaging technologies, fan-out packaging technology has been widely used in recent years because of its advantages of high integration, high fabrication flexibility, simple process and low process cost. However, the traditional fan-out wafer-level package (FOWLP) and fan-out board-level package (FOPLP) are mainly aimed at CMOS chip packaging applications, and they face many technical problems in compound RF chip packaging applications, such as RF grounding, heat dissipation of high-power RF chips, air bridge protection of RF chips and signal transmission in vertical. In view of the above problems, this paper proposes a fanout technology based on silicon-based TSV interposer. By making silicon-based interposer with two different depths of TSV, deep TSV is used for vertical interconnection of signals, and shallow TSV is used for grounding of RF chips. After the interposer is prepared, a cavity is dry etched on the back of shallow TSV for chip embedding. The chip is bonded in the cavity with conductive adhesive with high thermal conductivity. After the bonding process, the vacuum gluing technology is used to spin-coat polyimide as a passivation isolation layer between the chip and the RDL layer. In this paper, a silicon-based Fanout integration of GaAs chip has been successfully fabricated, and the RF performance has almost no attenuation compared with the die mounting test. Results On the surface, the silicon-based fanout technology proposed in this paper can realize the lossless packaging of compound chips with air bridge structure, and has good grounding and heat dissipation performance, which has obvious technical advantages compared with the traditional Fanout technology.

Keyphrases: Fanout, RF microsystem, TSV interposer

@booklet{EasyChair:13440,
  author    = {Jiao Zonglei and Li Jie and Wang Zhengyan and Zhang Hongze},
  title     = {A Silicon-Based Fanout Technology with High Aspect Ratio TSV for RF Heterogenous Integration Applications},
  howpublished = {EasyChair Preprint 13440},
  year      = {EasyChair, 2024}}