Materials & Surface Finishes Guide

PCB Materials &
Surface Finishes

Select the PCB material and surface finish according to your electrical, thermal, mechanical and assembly requirements.

Compare the material and finish options available for your PCB before finalizing the stack-up and production files.

9+ Surface Finish Options

Rogers / Ceramic / Flex

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PCB material cross-sections and surface finish samples -- FR4, Rogers, Flex, ENIG, HASL

FR4 Core Rogers RF ENIG Finish Flex / FPC

Materials

PCB Materials We Support

PCB material affects signal performance, heat dissipation, mechanical reliability, operating temperature and manufacturing cost. Use the options below to identify the material family that best fits your design.

FR4 & High-Tg PCB Materials

Choose the FR4 material according to operating temperature, thermal cycling, environmental requirements and PCB stack-up.

Material Option	When to Use It
Standard FR4	General-purpose choice for standard rigid and multilayer PCBs where normal thermal performance is sufficient.
High-Tg FR4	Choose for higher operating temperatures, repeated thermal cycling or applications requiring better dimensional stability.
Halogen-Free FR4	Use when your project specifies halogen-free laminate or related environmental material requirements.
Lead-Free Compatible FR4	Suitable for PCB assemblies exposed to higher lead-free reflow temperatures.
FR4 for Controlled Impedance	Suitable for high-speed single-ended or differential signals where dielectric thickness and trace geometry must be controlled.
FR4 for Heavy Copper	Used for power electronics and high-current PCB designs requiring thicker copper conductors.
Hybrid / Mixed-Material Stack-Up	Combine FR4 with RF or specialty laminates when different electrical or thermal characteristics are required within one PCB.

FR4 PCB multilayer stack-up cross-section showing copper, prepreg and core layers

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RF & High-Frequency PCB Materials

Select RF materials according to frequency, dielectric constant, insertion loss, impedance requirements and stack-up structure.

Material Option	When to Use It
Rogers RO4003C	Suitable for RF and microwave circuits requiring controlled dielectric properties with relatively straightforward multilayer processing.
Rogers RO4350B	Common choice for multilayer RF, microwave and high-frequency PCB designs.
RT/duroid 5880	Suitable for very low-loss microwave and high-frequency applications.
Rogers RO3000 Series	Used for RF and microwave designs requiring stable dielectric characteristics.
PTFE Materials	Suitable for high-frequency applications where low dielectric loss is a priority.
Nelco Materials	Available for applicable high-speed digital and RF PCB requirements.
RF / FR4 Hybrid Stack-Up	Use RF laminate only on signal-critical layers while combining it with FR4 where appropriate for cost and mechanical requirements.

RF PCB hybrid stack-up showing Rogers RF layer combined with FR4 core

View Rogers PCB View RF & Microwave PCB

Flexible PCB Materials

Flex material selection depends on bending requirements, total thickness, copper structure, component areas and expected flex life.

Material Option	When to Use It
Polyimide Flex Material	Standard choice for flexible circuits requiring thin construction and repeated bending capability.
Adhesive-Based Flex Material	Suitable for many standard flex PCB constructions where cost and conventional processing are important.
Adhesiveless Flex Material	Choose when reduced thickness, tighter bend radius or improved thermal performance is required.
Coverlay	Protects flexible circuit traces while exposing pads and contact areas for assembly.
PI Stiffener	Provides local reinforcement while keeping the structure relatively thin.
FR4 Stiffener	Commonly used around connectors, component areas and mechanical attachment points.
Controlled-Impedance Flex Construction	Used for high-speed flex circuits where material thickness and trace geometry must be controlled.

Flexible PCB cross-section showing coverlay, copper, polyimide and stiffener layers with bend illustration

View Flex PCB View Rigid-Flex PCB

Metal Core PCB Materials

Choose the metal base and dielectric structure according to heat generation, required thermal transfer and electrical insulation.

Material Option	When to Use It
Aluminum Core	Suitable for LEDs, lighting, power supplies and electronics requiring improved heat transfer at controlled cost.
Copper Core	Choose for higher-power or higher-heat-flux applications requiring stronger thermal transfer than typical aluminum-core structures.
Thermal Dielectric	Separates the circuit copper from the metal base while transferring heat into the metal core.
High-Copper Circuit Layer	Used when the PCB must carry higher current in addition to dissipating heat.
Thermal Via Structure	Used in applicable constructions to move heat from component areas into lower thermal layers or heat-spreading structures.

Metal core PCB cross-section showing circuit copper, thermal dielectric and aluminum or copper base

View Aluminum PCB View Copper Core PCB

Ceramic PCB Materials

Ceramic substrates are selected where electrical insulation, thermal performance and dimensional stability are more important than conventional FR4 construction.

Material / Structure	When to Use It
Alumina -- Al₂O₃	Suitable for power electronics, sensors and applications requiring good electrical insulation and thermal performance.
Aluminum Nitride -- AlN	Choose when substantially higher thermal conductivity is required while maintaining electrical insulation.
Silicon Nitride -- Si₃N₄	Suitable for demanding power applications where thermal performance and mechanical reliability are both important.
LTCC	Used for applicable multilayer ceramic circuits and compact electronic structures.
DBC	Suitable for high-power ceramic substrates using directly bonded copper conductors.
AMB	Used for applicable high-power modules requiring strong ceramic-to-copper bonding and mechanical reliability.

Ceramic PCB substrate comparison showing Al2O3, AlN and Si3N4 with copper bonded layers

View Ceramic PCB View Alumina PCB View Aluminum Nitride PCB

Specialty & Hybrid PCB Materials

Use specialty or mixed-material constructions when one standard laminate cannot meet all electrical, thermal or mechanical requirements of the PCB.

Material / Structure	When to Use It
CEM-1	Suitable for applicable cost-sensitive single-sided PCB applications.
RCC	Used in applicable HDI and build-up structures requiring thin dielectric layers.
Halogen-Free Materials	Selected where the project specifies applicable halogen-free material requirements.
High-Tg Materials	Suitable for higher operating temperatures and repeated thermal cycling.
Mixed FR4 / RF Materials	Used when only selected signal layers require RF or low-loss laminate.
Mixed Copper Weight Stack-Up	Suitable when different current or thermal requirements exist across different PCB layers.
Embedded R/C Structures	Available for applicable designs requiring embedded resistor or capacitor structures.

Hybrid PCB stack-up showing FR4, Rogers RF laminate, different copper weights and special dielectric layers

Hybrid constructions are confirmed during engineering review based on your stack-up and performance requirements.

Surface Finishes

PCB Surface Finishes We Support

The PCB surface finish protects exposed copper and creates the interface for soldering, wire bonding or electrical contact. Select the finish according to component pitch, assembly process, storage requirements, contact wear and project cost.

HASL

HASL coats exposed copper with solder and then levels the surface using hot air. It is a practical and cost-effective choice for many standard PCB designs.

Surface Flatness	Moderate
Fine-Pitch Components	Limited compared with flatter finishes
Solderability	Good
Lead-Free	No
Relative Cost	Low
Best For	Standard PCB, through-hole and general electronics

Choose HASL when cost and robust solderability matter more than extremely flat pads.

Comparison

Compare PCB Surface Finishes

Use this comparison as a starting point. Final finish selection should also consider component packages, assembly process, storage conditions and application requirements.

Surface Finish	Flatness	Fine-Pitch	Lead-Free	Wear Resistance	Relative Cost	Typical Fit
HASL	Moderate	Fair	No	Moderate	Low	Standard PCB / THT
Lead-Free HASL	Moderate	Fair	Yes	Moderate	Low-Medium	General lead-free PCB
ENIG	Excellent	Excellent	Yes	Good	Medium-High	BGA / QFN / HDI
Immersion Silver	Excellent	Excellent	Yes	Moderate	Medium	RF / Fine-Pitch
Immersion Tin	Excellent	Good	Yes	Moderate	Medium	Fine-Pitch / Press-Fit
OSP	Excellent	Excellent	Yes	Low	Low	High-volume SMT
Hard Gold	Good	Application-specific	Yes	Excellent	High	Gold Fingers / Contacts

Selection Guide

How to Select the Right
PCB Surface Finish

Fine-Pitch, BGA or QFN

Prioritize a flat surface such as ENIG, OSP, Immersion Silver or Immersion Tin when pad flatness is critical to assembly.

Gold Fingers or Repeated Contact

Use Hard Gold where connector contacts must withstand repeated insertion or mechanical wear.

Standard PCB With Cost Priority

HASL or Lead-Free HASL is often practical when component pitch permits and cost is an important purchasing factor.

RF & High-Frequency PCB

Evaluate the laminate, copper structure and surface finish together because conductor characteristics can affect high-frequency performance.

Storage & Reliability Requirements

Consider storage time, packaging conditions, number of reflow cycles and final application environment before selecting the finish.

Engineering Note

Confirm Materials
Before Production

Material brand, dielectric thickness, copper weight, stack-up and surface finish can affect both PCB performance and manufacturability. Send your Gerber files, stack-up and project requirements if you are unsure which material or finish fits your design.

Final material availability and non-standard specifications are subject to engineering confirmation before order acceptance.

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Wear Resistance	Excellent
Connector Contacts	Excellent
Gold Fingers	Well suited
Primary Solder Finish	Normally not selected for the complete solderable PCB surface
Mechanical Durability	High
Relative Cost	High
Best For	Edge connectors, card fingers, switches and contact surfaces

PCB Materials & Surface Finishes