Intel EMIB (Embedded Multi-die Interconnect Bridge)

EMIB (Embedded Multi-die Interconnect Bridge) is an advanced 2.5D packaging technology developed by Intel that enables high-density, high-bandwidth, low-latency interconnects between chiplets (dies) within a single package—without requiring a full silicon interposer. EMIB offers a modular and scalable approach to heterogeneous integration, supporting CPUs, GPUs, memory (e.g., HBM), and accelerators in high-performance systems.

Introduced in 2014 and first used commercially in 2018 (in Intel’s Kaby Lake-G platform), EMIB is now a key part of Intel’s IDM 2.0 strategy and Intel Foundry Services (IFS) advanced packaging portfolio, often combined with other technologies like Foveros (3D stacking) and ODI (Omni-Directional Interconnect).

Overview

EMIB allows different dies to communicate efficiently within a single package using a small silicon bridge embedded into the package substrate. This bridge provides fine-pitch connections between adjacent dies—without the cost and complexity of a full silicon interposer used in traditional 2.5D solutions like TSMC CoWoS or Samsung I-Cube.

The EMIB bridge sits beneath the chiplets and offers short, dense interconnects for high-bandwidth, low-power, and high-yield integration.

Key Features

Feature	Description
2.5D Integration	Side-by-side die placement with localized interconnect
Embedded Bridge	Small silicon die embedded in the package substrate
High Interconnect Density	Fine-pitch micro-bump connections
No Full Interposer	Avoids large, costly silicon interposers
Heterogeneous Integration	Combines dies from different nodes, fabs, and functions
Flexible Design	Supports mix-and-match chiplets, scalable system design

How EMIB Works

A small silicon bridge (~a few mm wide) is embedded into the organic package substrate during manufacturing.
Two or more adjacent chiplets (e.g., CPU + GPU, CPU + HBM) are placed over the substrate, aligning with the EMIB.
Each die connects to the EMIB through micro-bumps, creating a dense, short interconnect path across dies.
High-speed signals, clocking, and power distribution traverse the bridge.
There is no need for TSVs (through-silicon vias) or a large interposer wafer.

Advantages of EMIB

Lower Cost: Avoids the expense of a full interposer wafer.
Smaller Footprint: More compact than interposer-based designs.
Better Thermal Management: Improved heat dissipation vs. stacked dies.
High Bandwidth: Comparable to 2.5D silicon interposer designs.
Modularity: Easier to upgrade or customize individual chiplets.
Yield Benefits: Improves yield by integrating known-good dies (KGD).

Applications

EMIB is used in a variety of high-performance and modular products:

Intel Products:

Kaby Lake-G (Intel CPU + AMD Vega GPU + HBM2 via EMIB)
Intel Stratix 10 FPGA (logic + transceivers via EMIB)
Ponte Vecchio (Xe HPC GPU with over 47 chiplets)
Meteor Lake (Modular client SoC combining CPU, GPU, SoC dies)
Falcon Shores (future XPU architecture for AI/HPC)

IFS & Partner Projects:

Intel offers EMIB to foundry customers via Intel Foundry Services
Can be combined with UCIe for standardized die-to-die communication

EMIB vs. Other Packaging Technologies

Feature	EMIB	TSMC CoWoS	Intel Foveros	Samsung I-Cube
Type	2.5D	2.5D	3D	2.5D
Interposer	Embedded bridge	Full silicon	Die stacking	Interposer
TSVs	No	Yes	Yes	Yes
Memory Integration	Yes (HBM)	Yes	Yes	Yes
3D Stacking	No	No	Yes	No
Cost	Lower	Higher	Medium–High	Medium

EMIB + Foveros: Intel’s Advanced Packaging Stack

Intel often combines EMIB and Foveros in a single design:

EMIB: For horizontal, high-bandwidth die-to-die links (e.g., HBM integration, GPU+GPU, SoC+I/O)
Foveros: For vertical stacking of logic on logic (CPU-on-SoC, cache-on-CPU)

This hybrid approach powers products like Ponte Vecchio and enables modular SoC disaggregation with heterogeneous integration.

EMIB and UCIe

Intel is a founding member of the UCIe (Universal Chiplet Interconnect Express) consortium. EMIB serves as a physical interconnect fabric in Intel’s chiplet ecosystem, and it supports UCIe-based communication for standardization across chiplet providers.

Challenges

Precision Alignment: Requires accurate die placement over small bridges
Design Complexity: Needs co-design between silicon, bridge, and substrate
Thermal Isolation: Must manage heat between adjacent high-power dies
EDA Tooling: Integration flows differ from conventional SoC designs

Future Directions

EMIB roadmap includes higher lane speeds, greater link density, and larger bridge arrays
ODI (Omni-Directional Interconnect) extends EMIB to support vertical and horizontal connectivity
Next-gen HBM4 and multi-tile AI accelerators will further drive EMIB adoption
Intel Foundry Services (IFS) is building EMIB into its open packaging ecosystem for external customers