Next Generation of Automotive Radar with Leading-Edge Advances in SiGe Devices and Glass Panel Embedding (GPE)

The design and process building blocks for an ultra-miniaturized automotive radar module were demonstrated with the most leading-edge SiGe devices operating at 77 GHz and 3D glass panel embedded (GPE) package. The key advances with such a package include: (1) advanced SiGe BiCMOS 77 GHz automotive radar receiver with improved detection range and signal-to-noise ratio (SNR), (2) ultra-miniaturized module and low-loss interconnections by GPE packaging, (3) improved board-level reliability enabled by the tailorability of the CTE of the glass panels and compliant interconnections, (4) innovative chip-package co-design and (5) large area panel-scalable glass substrate processes for potentially lower cost. To demonstrate this automotive radar module, low-noise amplifier (LNA) and mixer chips for 77 GHz automotive radar receiver were first designed, and then fabricated using IBM 8HP 130nm technology with the size of 5mm x 5mm and thickness of 250 μm. Glass panels with 300 μm thickness and through glass cavities were fabricated with cavity location and dimensional accuracy below +5 μm, and then then bonded on a 100 μm thick glass panel carrier using adhesive bonding. After glass-to-glass bonding, the designed 77GHz radar chips were placed in the glass cavities using a high-speed placement tool from Kulicke and Soffa. RDL polymers were then laminated and cured on both sides to minimize the warpage of package. A UV laser tool from ESI was then used to drill the microvias to interconnect the chip to the fan-out RDL layer by a standard semi-additive process (SAP). Initial modeling and measured results indicate the potential for an ultra-miniaturized automotive radar module with high-linearity, low noise figure below 10dB and low-loss chip-package interconnection.