Adv Packaging InFO (Integrated Fan-Out)

InFO (Integrated Fan-Out) is TSMC’s advanced fan-out wafer-level packaging (FO-WLP) technology. Unlike CoWoS, which relies on a silicon interposer, InFO redistributes I/O directly over a reconstituted wafer using redistribution layers (RDL). This allows for ultra-thin packages with high-density interconnects and excellent electrical performance, making InFO a leading choice for mobile, consumer, and lightweight compute devices.

Process Overview

• Step 1: Dies are embedded into an epoxy mold compound to create a reconstituted wafer.
• Step 2: Redistribution layers (RDLs) are built on top, rerouting I/O pads to a larger pitch.
• Step 3: Additional dies (logic, memory, RF) may be integrated side-by-side for system-in-package designs.
• Step 4: Solder balls or copper pillars are applied for board-level connections.
• Step 5: Packages are singulated and tested before shipment.

Key Features

• Ultra-Thin Profile: No silicon interposer, resulting in reduced z-height (suitable for smartphones and wearables).
• High-Density I/O: Redistribution layers enable higher pad counts and finer interconnect pitch.
• System-in-Package (SiP): Supports side-by-side heterogeneous integration (logic + memory + RF).
• Scalability: Compatible with both single-die and multi-die integration.

Applications

• Mobile SoCs: Widely adopted in Apple iPhone A-series and M-series chips.
• Wearables: Enables small, thin packages with high-performance logic and RF integration.
• Consumer Electronics: Provides cost-effective high-density packaging for tablets and lightweight devices.

Representative Customers

Advantages & Constraints

• Advantages: Thin profile; reduced package parasitics; high-density interconnects without expensive interposers; scalable for multi-die SiP.
• Constraints: Limited to smaller die and package sizes vs CoWoS; not suitable for ultra-high-bandwidth AI/HPC needs; warpage challenges in large formats.

Cleanroom & Environment

• Performed in Class 1000–10,000 assembly environments.
• Requires precise warpage control during mold reconstitution and RDL formation.
• Reliability testing critical for moisture and thermal cycling due to thin profiles.

Market Outlook

InFO has become the dominant advanced packaging solution in mobile, with Apple driving its early adoption. TSMC continues to expand InFO variants such as InFO-MS (multi-stack), InFO-PoP (package-on-package), and InFO-oS (on-substrate). Through 2030, InFO will remain central to consumer and edge devices, while CoWoS and 3D hybrid bonding dominate AI/HPC packaging. OSATs are developing competing fan-out solutions, but TSMC’s InFO ecosystem remains the market leader.