Low Dk/Df Siloxane Hybrid Laminates for Advanced Packaging Substrate

Advanced packaging technologies are irreplaceable in enabling next-generation semiconductor devices, driving advanced electronic devices like the Internet of Things (IoT), the metaverse, and artificial intelligence (AI). In particular, packaging substrates with low dielectric constant (Dk) and dissipation factor (Df) are essential for minimizing signal loss in high-speed devices. Recently, various manufacturers have introduced their own low Dk/Df materials for advanced packaging substrates, including liquid crystal polymer (LCP), modified polyimide (MPI), and modified polyphenylene ether (MPPE). However, the widespread adoption of these materials in integrated circuits (ICs) remains challenging due to issues such as anisotropic properties, high water absorption, and processing difficulties. Here, we present low Dk/Df siloxane hybrid laminates, consist of 3 types of siloxane hybrid materials as matrices (Singi G/C/F, G: extremely low Df, C: high processability, F: high flexibility) and two different type of glass fabric (Quartz/NE), for novel advanced packaging substrate materials of next generation semiconductor devices. The fabricated siloxane hybrid laminates (Q-Singi G/C/F, NE-Singi G/C/F) showed low Dk (Q-Singi G/C/F: 3.2/3.3/3.2, NE-Singi G/C/F: 3.4/3.5/3.4) and Df (Q-Singi G/C/F: 0.0014/0.0017/0.0018, NE-Singi G/C/F: 0.0022/0.0024/0.0025) at 10 GHz. Especially, Q/NE-Singi G and NE-Singi C showed low Dk ($<3.3$ and $<3.6$) and Df ($<0.0022$ and $<0.0035$) at wide GHz frequency ranges of 2.5-50 GHz. Moreover, our siloxane hybrid laminate showed low coefficient of thermal expansion (CTE) ($<20 \text{ppm} /{ }^{\circ} \mathrm{C}$) with superior mechanical characteristics. Finally, microstrip test coupon was successfully demonstrated by using Q-Singi G based double sided copper clad laminates (CCLs) with Cu foil of low surface roughness. The coupon showed low transmission loss in wide frequency ranges from 0.1 to 40 GHz.