Build-up Materials Material Guide

Overview

Build-up Materials are specialized dielectric and insulating materials used in High Density Interconnect (HDI) PCBs, IC Substrates, and Advanced Semiconductor Packaging. These materials enable the creation of ultra-fine circuit patterns, microvias, sequential lamination structures, and high-density multilayer interconnects required in modern electronic devices.

Unlike conventional PCB prepregs and laminates, Build-up Materials are specifically engineered for laser-drilled microvias, ultra-thin dielectric layers, low dielectric loss, and high reliability under thermal cycling conditions.

Build-up Materials are widely used in:

  • HDI PCBs
  • Semiconductor Substrates
  • AI Accelerators
  • High-Performance Computing (HPC)
  • Data Center Hardware
  • Smartphones
  • Advanced Packaging
  • Automotive Electronics

As electronic devices continue to shrink while increasing functionality, Build-up Materials have become a critical technology for next-generation electronics manufacturing.


Material Specification

PropertyValue
Material DesignationBuild-up Materials
Full NamePCB Build-Up Dielectric Materials
Material FamilyAdvanced PCB Dielectrics
Typical Thickness10–100 μm
Dielectric Constant (Dk)2.8–4.0
Dissipation Factor (Df)0.002–0.015
Glass Transition Temperature (Tg)150–250°C
Manufacturing MethodSequential Lamination

Material Structure

Build-up Materials are typically applied as thin dielectric layers between conductive copper layers.

LayerFunction
Copper LayerSignal Routing
Build-up DielectricElectrical Insulation
Laser MicroviaVertical Interconnection
Core MaterialMechanical Support
Surface FinishComponent Assembly

These materials enable the formation of stacked and staggered microvia structures.


Common Build-up Material Types

Material TypeCharacteristics
ABF (Ajinomoto Build-up Film)Semiconductor Substrates
RCC (Resin Coated Copper)Thin HDI Structures
Build-Up Epoxy FilmsStandard HDI Applications
Polyimide Build-Up FilmsHigh Temperature Applications
Low Loss Build-Up MaterialsHigh-Speed Digital Systems
RF Build-Up MaterialsHigh-Frequency Applications

Common Build-up Material Systems

Material FamilyApplication
ABFCPU, GPU, AI Chips
BT Resin Build-UpIC Packaging
Epoxy Build-Up FilmsHDI PCB Manufacturing
Polyimide FilmsAerospace Electronics
Low-Loss LaminatesHigh-Speed Computing

ABF is currently the dominant material for advanced semiconductor package substrates.


Mechanical Properties

Typical Values

PropertyValue
Tensile Strength80–180 MPa
Flexural Strength100–250 MPa
Elastic Modulus2–10 GPa
Dimensional StabilityExcellent
Via ReliabilityOutstanding

Mechanical Performance

PropertyPerformance
Layer AdhesionExcellent
Microvia ReliabilityOutstanding
Thermal Cycling ResistanceExcellent
Structural StabilityExcellent

Build-up materials are optimized for multilayer reliability.


Physical Properties

PropertyValue
Density1.1–1.8 g/cm³
Moisture AbsorptionVery Low
Surface RoughnessExtremely Low
FlatnessExcellent
Dimensional StabilityOutstanding

Low surface roughness is critical for high-speed signal integrity.


Thermal Properties

PropertyValue
Glass Transition Temperature (Tg)150–250°C
Decomposition Temperature (Td)>300°C
Continuous Service Temperature130–180°C
Thermal Expansion ControlExcellent
Lead-Free CompatibilityOutstanding

Modern build-up materials are designed for repeated lead-free reflow cycles.


Electrical Properties

Typical Values

PropertyValue
Dielectric Constant (Dk)2.8–4.0
Dissipation Factor (Df)0.002–0.015
Volume Resistivity>10¹⁴ Ω·cm
Surface Resistivity>10¹³ Ω
Dielectric StrengthExcellent

Electrical Performance

PropertyPerformance
Signal IntegrityOutstanding
High-Speed Digital PerformanceOutstanding
Impedance ControlExcellent
Crosstalk ReductionExcellent

Build-up materials are essential for modern high-speed computing platforms.


Microvia Performance

PropertyPerformance
Laser DrillabilityOutstanding
Via Formation AccuracyOutstanding
Stacked Via CompatibilityExcellent
Staggered Via CompatibilityExcellent

Microvia performance is one of the defining characteristics of build-up materials.


Thermal Reliability

PropertyPerformance
Thermal Shock ResistanceExcellent
Delamination ResistanceOutstanding
Via Fatigue ResistanceOutstanding
CAF ResistanceExcellent

High reliability under thermal cycling is critical for semiconductor packaging applications.


Moisture Resistance

PropertyPerformance
Water AbsorptionVery Low
Humidity ResistanceExcellent
Electrical StabilityExcellent
Long-Term ReliabilityOutstanding

Low moisture absorption improves package and PCB reliability.


Manufacturing Characteristics

Manufacturing ProcessRating
Sequential LaminationOutstanding
Laser DrillingOutstanding
HDI PCB ManufacturingOutstanding
IC Substrate FabricationOutstanding
Advanced PackagingOutstanding

Build-up materials are specifically designed for advanced electronics manufacturing.


International Standards

StandardCompliance
IPC-4101Applicable
IPC-6016Applicable
RoHSCompliant
REACHCompliant
JEDEC Packaging StandardsSupported

Available Forms

Product TypeAvailability
Build-Up FilmYes
Dielectric FilmYes
Resin Coated CopperYes
Semiconductor Substrate MaterialYes
HDI Dielectric MaterialYes

Typical Applications

Semiconductor Packaging

  • CPU Substrates
  • GPU Substrates
  • AI Accelerators
  • Chiplet Packages

High Performance Computing

  • Server Processors
  • HPC Modules
  • Data Center Hardware
  • Networking Equipment

Consumer Electronics

  • Smartphones
  • Tablets
  • Wearables
  • AR/VR Devices

Automotive Electronics

  • ADAS Systems
  • Autonomous Driving Controllers
  • Radar Modules
  • EV Electronics

Telecommunications

  • 5G Infrastructure
  • Optical Networking
  • High-Speed Communication Systems

Aerospace & Defense

  • Avionics Electronics
  • Communication Systems
  • Mission-Critical Computing

Advantages

Supports Ultra-High Density Interconnects

Enables advanced routing densities beyond traditional PCB materials.

Excellent Microvia Reliability

Designed for stacked and staggered microvia structures.

Outstanding Signal Integrity

Supports high-speed digital and AI computing applications.

Advanced Packaging Compatibility

Widely used in semiconductor substrates and chip packaging.

Superior Thermal Reliability

Performs reliably under repeated thermal cycling.

Future-Proof Technology

Critical for AI, HPC, 5G, and next-generation electronics.


Limitations

Higher Cost

More expensive than conventional PCB dielectric systems.

Complex Manufacturing

Requires advanced fabrication equipment and expertise.

Tight Process Control Requirements

Manufacturing tolerances are significantly more demanding.

Limited Supplier Base

Only a small number of manufacturers produce advanced build-up materials.


Comparison with PCB Dielectric Materials

PropertyBuild-up MaterialsStandard FR4High Tg FR4ABF
Routing DensityOutstandingModerateModerateOutstanding
Microvia SupportOutstandingLimitedLimitedOutstanding
Signal IntegrityOutstandingGoodGoodOutstanding
Semiconductor PackagingExcellentPoorPoorOutstanding
CostHighLowModerateVery High

Comparison with Standard PCB Materials

PropertyBuild-up MaterialsStandard PCB Dielectrics
Layer ThicknessMuch Thinner
Microvia CapabilitySuperior
Signal PerformanceBetter
Package DensityHigher
Manufacturing ComplexityHigher

Build-up materials are essential for HDI PCBs and semiconductor substrate technologies.


Available Surface Finishes

Standard Finishes

  • Copper-Clad Surface
  • Build-Up Film Surface
  • Resin-Coated Copper Surface

Functional Finishes

  • Semiconductor Package Surface
  • High-Speed Digital Surface
  • HDI PCB Surface

Specialty Configurations

  • ABF Materials
  • RCC Materials
  • Epoxy Build-Up Films
  • Polyimide Build-Up Films
  • Low-Loss Build-Up Dielectrics

Frequently Asked Questions (FAQ)

What are Build-up Materials?

Build-up Materials are advanced dielectric materials used in HDI PCBs and semiconductor substrates to create microvias and high-density interconnect structures.

What are Build-up Materials used for?

Typical applications include:

  • HDI PCBs
  • CPU Substrates
  • GPU Substrates
  • AI Accelerators
  • Advanced Semiconductor Packaging

What is ABF?

ABF (Ajinomoto Build-up Film) is the most widely used build-up material for semiconductor package substrates.

Why are Build-up Materials important?

They enable ultra-high-density circuit routing, advanced packaging technologies, and next-generation electronic systems.

Are Build-up Materials suitable for high-speed computing?

Yes. Many build-up materials are specifically optimized for AI, HPC, networking, and high-speed digital applications.

Why choose Build-up Materials?

Because they provide:

  • High Routing Density
  • Microvia Capability
  • Excellent Signal Integrity
  • Advanced Packaging Compatibility
  • Outstanding Reliability

What is the difference between Build-up Materials and FR4?

Build-up materials support much thinner dielectric layers, finer routing, microvias, and higher performance compared with conventional FR4 materials.

Does GCNOV provide HDI and Build-up PCB manufacturing services?

Yes. GCNOV provides:

  • HDI PCB Manufacturing
  • Build-Up PCB Fabrication
  • Microvia PCB Production
  • Semiconductor Substrate Support
  • High-Speed PCB Solutions
  • Prototype Development
  • Low-Volume Production
  • Mass Production