ABF (Ajinomoto Build-up Film) Substrate
Dk 2.9-3.3 | Df 0.003-0.005 | 2/2um L/S — the Ajinomoto monopoly material enabling every advanced processor and AI chip package.
2.9-3.3
Dk
2/2 um
L/S Capable
Ajinomoto
Sole Source
AI/HPC
Critical
What is ABF Substrate?
ABF (Ajinomoto Build-up Film) is a dry-film dielectric material produced exclusively by Ajinomoto Fine-Techno (a subsidiary of the Japanese food company) that has become the most critical material in advanced semiconductor packaging. Every high-performance processor package from Intel, AMD, NVIDIA, Apple, and Qualcomm relies on ABF for build-up layer construction.
ABF enables the ultra-fine line/space (2-5um L/S) required for advanced flip-chip packages. The film is laminated onto the substrate core, then laser-drilled and plated using semi-additive processing (SAP) to create redistribution layers (RDL) that route thousands of signals between the die and BGA ball array.
Ajinomoto's position as sole-source supplier for this critical material has created one of the semiconductor industry's most acute supply chain vulnerabilities. ABF capacity constraints directly limit global production of AI accelerators, high-end CPUs, and networking ASICs — making it perhaps the most strategically important material in the AI hardware supply chain.
2/2um Line/Space
Finest patterning of any package build-up dielectric available.
Low-Dk/Df for Speed
Dk 2.9-3.3 with Df 0.003-0.005 for high-speed die-to-package signaling.
Every AI Chip
Under NVIDIA, AMD, Intel, Apple AI and HPC processors.
SAP Compatible
Optimized for semi-additive plating to achieve finest features.
ABF Substrate Key Properties
Representative values from the manufacturer datasheet.
| Property | Value | Why it matters |
|---|---|---|
| Dielectric constant (Dk) | 2.9-3.3 @ 1 GHz (grade dependent) | Multiple grades for different performance tiers. |
| Dissipation factor (Df) | 0.003-0.005 @ 1 GHz | Low loss for high-speed die-to-package channels. |
| Line/space capability | 2/2 um (advanced SAP) | Finest production patterning in package substrates. |
| Film thickness | 15-45 um per layer | Multiple thicknesses for different layer functions. |
| CTE | 30-60 ppm/C (above Tg) | Managed with appropriate package design. |
| Tg | 180-210 C | Stable through multiple reflow cycles. |
| Peel strength | 0.5-0.8 kN/m | Adequate adhesion for fine-line copper plating. |
| Via diameter | 20-50 um laser | Conformal laser via for high-density vertical interconnect. |
| Layer count | 2-20+ build-up layers | Complex packages for highest-end processors. |
ABF: The Hidden Bottleneck of AI Hardware
The AI hardware supply chain has a chokepoint most people do not see: Ajinomoto Build-up Film. Every NVIDIA H100, B200, and successor GPU package requires approximately 10-16 ABF layers. Every AMD MI300, Intel Gaudi, and custom AI ASIC requires similar. As AI training cluster deployments scale to millions of GPUs, ABF production capacity becomes a binding constraint on global AI compute expansion.
Ajinomoto controls approximately 90%+ of the global ABF market. Despite capacity expansions, demand consistently outpaces supply during AI investment cycles. This single-source dependency has prompted major semiconductor companies and governments to fund alternative dielectric development programs — but ABF's process-optimization legacy of 20+ years makes displacement extremely difficult.
The physics of ABF are what make it irreplaceable: its thermoplastic properties enable uniform lamination without bubble entrapment, its laser-ablation characteristics produce clean via shapes, and its copper adhesion profile supports the electroless seed and SAP plating sequence that achieves 2um L/S. No other material has been optimized across all these dimensions simultaneously.
AI Hardware Backbone
Required for every advanced AI GPU and accelerator package in production.
20+ Year Process Heritage
Two decades of optimization makes ABF virtually irreplaceable.
Sole-Source Strategic
Ajinomoto 90%+ market share — geopolitically significant supply chain.
Multi-Layer Build-Up
10-20 ABF layers in complex AI chip packages.
Package Build-Up Dielectric Comparison
ABF versus alternative build-up dielectrics for advanced packaging.
| Material | Dk | Df | Best For |
|---|---|---|---|
| ABF (Ajinomoto)This page | 2.9-3.3 | 0.003-0.005 | Industry standard — finest L/S, sole source, every AI chip. |
| Liquid PI (Photosensitive) | 3.2 | 0.008 | Alternative — coarser features, multiple sources, lower cost. |
| Low-Dk ABF (GX-92R) | 2.9 | 0.003 | Premium ABF — lowest loss for high-speed packages. |
| Dry-Film Solder Resist | 3.5 | 0.015 | Non-ABF build-up — much coarser, low-end packages. |
| BT Prepreg (Build-up) | 3.8 | 0.008 | Core-based — limited to 15um+ L/S, no ABF advantage. |
ABF Substrate Applications
Advanced processor packages, AI accelerators, HPC chips, networking ASICs, advanced memory controllers
AI Accelerator Packages
NVIDIA, AMD, and custom AI ASIC substrates for training and inference.
High-End Processors
Intel, AMD, Apple, and Qualcomm flagship processor packages.
Networking ASICs
Broadcom, Marvell, and custom 800G+ switch chip packages.
HBM Controllers
Memory controller dies in HBM stacks requiring fine-pitch interconnect.
Automotive Compute
Autonomous driving SoC packages (NVIDIA Drive, Mobileye).
Space-Grade Processors
Radiation-hardened processor packages for satellite compute.
ABF Substrate Design Guidelines
ABF substrate design is performed by specialized package substrate design houses using dedicated EDA tools (Cadence APD, Siemens Xpedition Substrate Integrator). Standard PCB design tools cannot handle the feature scales and design rules involved. Engage your OSAT or substrate vendor's design team early.
ABF layer count directly impacts package cost. Each ABF layer adds approximately $15-30 to package substrate cost at volume. Optimize I/O routing to minimize layer count — going from 12 to 10 ABF layers on a 100K unit production saves $300K-600K.
Get Instant QuoteSpecialized EDA Required
Cadence APD or equivalent — standard PCB tools cannot handle ABF design.
Minimize Layer Count
Each ABF layer adds $15-30. Optimize routing to reduce layers.
Vendor DRM Compliance
Follow substrate vendor's specific ABF design rule manual precisely.
Via Stacking Rules
ABF via stack limits differ by vendor — typically 4-6 stacked maximum.
Genuine ABF Substrate, Verified on Every Order
Material CoC
Certificate of Conformance with lot number ships with every order.
Stock Verified
We confirm laminate availability before order confirmation.
No Substitutions
Specified material guaranteed — never swapped without written approval.
FAQ
ABF Substrate Questions
What is ABF substrate?
ABF (Ajinomoto Build-up Film) is a dry-film dielectric material used to create the ultra-fine redistribution layers in advanced IC package substrates. Produced exclusively by Ajinomoto.
Why is ABF sole-sourced?
Ajinomoto developed ABF over 20+ years with process optimization across lamination, laser drilling, and plating chemistry. This accumulated know-how makes competitive displacement extremely difficult.
What AI chips use ABF?
All of them. Every NVIDIA GPU (H100, B200+), AMD MI-series, Intel Gaudi, Apple M-series, and Qualcomm Snapdragon uses ABF substrate packaging.
What is the finest L/S possible with ABF?
Production: 2/2um L/S with advanced SAP. Research: sub-2um demonstrated. Standard production typically runs at 5-8um for cost optimization.
Can AtlasPCB produce ABF substrates?
We offer ABF substrate fabrication through our advanced packaging division with SAP capability to 5um L/S. Contact engineering for advanced node assessment.
Need advanced package substrate fabrication?
ABF substrates — 2-5um L/S, SAP processing — for AI accelerators and advanced processors. Contact our packaging team.
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