embedded die process substrate

**Embedded Die in Substrate** enables **direct integration of semiconductor dies within organic substrate using blind via interconnection, eliminating need for separate package and reducing interconnect parasitic resistance**. **Via-in-Die Concept:** - Blind vias: laser-drilled vias from substrate surface reaching die pads (sub-surface) - Via-in-die vias: penetrate die substrate (requires special die preparation) - Direct connectivity: minimal parasitic resistance vs wirebond/BGA - High current capability: direct path ideal for power applications **Die Embedding Substrate Options:** - Coreless substrate: no fiber-glass core, pure resin material for embedding - Cored substrate: FR-4 glass-fiber core with resin, die embedded within - Die cavity: controlled depression for die placement - Resin fill: hermetic encapsulation around die **Process Flow (Build-Up Layer Technology):** - Core preparation: (if cored) or resin foundation (if coreless) - Die placement: adhesive positioning in cavity - Via drilling: laser punch blind vias to die pads - Via metallization: Cu plating into blind vias - Lamination cycles: layer-by-layer buildup (dielectric + conductive layers) - Final processing: outer layer RDL, solder pads **Via Density and Pitch:** - Blind via diameter: 50-150 µm typical (laser drilling limitation) - Via pitch: 200-300 µm conservative (tighter spacing possible) - Via density: 100-200 vias per die typical - Interconnect bandwidth: improved vs wirebond (lower inductance) **Infineon Embedded Power Technology:** - Target applications: power management, integrated power stages - Die embedding into substrate layer directly - Reduces thermal path: embedded die improves heat dissipation - Advanced version: active substrate (passive components, impedance matching) **Reliability Considerations:** - Thermal cycling: embedded die experiences stress from substrate CTE mismatch - Moisture absorption: organic substrate absorbs water, creating swelling stress - Pad cratering: mechanical failure at die edge if stress too high - Mitigation: underfill, controlled resin chemistry, process optimization **Application Sweet Spots:** - Power management ICs: POL (point-of-load) converters - RF modules: embedded filters, matching networks - Analog modules: embedded reference circuits - Cost-sensitive: volume justifies process development **Advantages vs Other Technologies:** - vs wirebond: higher density, lower inductance - vs BGA: no substrate needed, shorter interconnect - vs flip-chip: potentially lower cost for low-current applications Embedded die represents mid-cost, high-density solution for power/analog applications requiring superior thermal/electrical performance relative to traditional wirebond/BGA packages.