Driven by the escalating chip-level heat flux demands of artificial intelligence and high-performance computing, thermal management has emerged as a critical bottleneck for next-generation microelectronic integration. To address the prominent contradiction between the limited space and the high heat flux in silicon interconnect fabric chips, this research has overcome the key challenge of miniaturizing traditional spray cooling by designing and implementing an ultra-thin spray cooling heat sink embedded in a silicon-based test chip. The core advancement stems from a synergistic integration of topology-optimized micro-nozzle architecture and silicon-based microfabrication, achieving a total spray module thickness of merely 3.5 mm and enabling uniform near-field atomization from four nozzles under low pressure. Experimental results demonstrate that the heat sink removes 614 W at a junction temperature of 92 °C from a compact footprint of 9.5 mm × 9.5 mm, yielding a peak surface heat transfer coefficient of 9.03 W/(cm²·K). This performance not only validates the feasibility of spray cooling in ultra-thin packaging architectures, but also presents one of the first experimental demonstration of the monolithic integration of a spray cooling system with a silicon-based integrated circuit. This work establishes a viable pathway for ultra-high heat flux thermal management under extreme spatial constraints, enabling the practical deployment of spray cooling in high-power-density electronics, including high-performance computing and artificial intelligence chips.