Structural Design and Wafer-level Processing of Quartz Crystal Oscillator Glass Package Based on Response Surface Optimization

To address the growing demand for miniaturized quartz crystal oscillators in 5G and IoT devices, this paper proposes a cost-effective, wafer-level glass packaging scheme using TGV technology. Traditional ceramic and metal packaging face limitations in integration, thermal stress management, and cost. A sandwich packaging structure (TGV substrate, MEMS quartz blank, silicon cap) compliant with the 1612 specification is designed. Thermal-mechanical simulations under 80°C loads, combined with Box-Behnken experiments, optimized TGV aperture, sidewall thickness, and cavity depth. Response surface models (R² = 99.93% for maximum stress; 98.96% for average stress) guided parameter adjustments, reducing maximum equivalent stress by 28.3% and improving average stress by 4.7%. A wafer-level process was implemented: laser-induced etching (60 μm TGV), copper/zinc-aluminum via filling, and direct silicon-glass anodic bonding for vacuum sealing. The packaged oscillator achieved 38.28 MHz frequency and frequency deviation within ±10 ppm. This work highlights a synergistic TGV-cavity design to mitigate thermal mismatch stress and a scalable fabrication flow, offering a low-cost, high-performance solution for next-generation quartz oscillator packaging.