Dielectric Core Material: Thickness Tolerance ±10%

Component Specifications

Definition

Dielectric core material is a specialized insulating substrate used in High-Density Interconnect (HDI) printed circuit boards. It serves as the foundational layer that separates conductive copper layers, preventing electrical short circuits while providing mechanical stability. This material features low dielectric constant (Dk) and dissipation factor (Df) to minimize signal loss and maintain signal integrity at high frequencies. It must withstand multiple lamination cycles during PCB fabrication while maintaining dimensional stability and thermal resistance.

Working Principle

The dielectric core material functions by providing electrical insulation between conductive copper layers in multilayer PCBs. Its low dielectric constant reduces signal propagation delay and capacitive coupling, while its low dissipation factor minimizes energy loss as heat. During PCB manufacturing, it undergoes lamination under heat and pressure to bond with copper foils, creating a rigid composite structure. The material's thermal expansion properties must match those of copper to prevent delamination during thermal cycling.

Materials

Typically composed of woven glass fiber reinforcement impregnated with epoxy resin (FR-4), polyimide, or specialized low-loss thermoset polymers. Advanced versions may use ceramic-filled composites or liquid crystal polymer (LCP) for high-frequency applications. Copper foil is laminated on both surfaces.

Technical Parameters

Parameter	Typical range	Notes & selection driver
Peel Strength	>1.0 N/mm
Flammability Rating	UL94 V-0
Thickness Tolerance	±10%
Dissipation Factor (Df)	0.008-0.02 @ 1 GHz
Dielectric Constant (Dk)	3.5-4.5 @ 1 GHz
Glass Transition Temperature (Tg)	140-180°C
Coefficient Of Thermal Expansion (CTE)	12-16 ppm/°C (X-Y), 40-70 ppm/°C (Z)
Thermal Decomposition Temperature (Td)	>300°C

Ranges are indicative industry figures for RFQ preparation, not a supplier commitment. Confirm every value and standard with the legal manufacturer before ordering.

Standards

IPC-4101, IPC-4103, IEC 61249-2, UL 746E

Parent Products

This component is used in the following industrial products

High-Density Interconnect (HDI) PCB Substrate

Advanced printed circuit board substrate enabling miniaturized electronic component integration

View Product Details

Engineering Analysis

Risks & Mitigation

Delamination under thermal stress
Moisture absorption affecting electrical properties
Dimensional instability during lamination
Inconsistent dielectric properties across batches

FMEA Triads

Trigger: Inadequate resin curing during manufacturing
Failure: Reduced thermal resistance leading to delamination
Mitigation: Implement strict cure cycle monitoring and post-cure quality testing

Trigger: Moisture absorption during storage
Failure: Increased dissipation factor and potential blistering during lamination
Mitigation: Vacuum-sealed packaging with desiccant and controlled storage conditions

Trigger: Inconsistent glass fiber weave density
Failure: Variations in dielectric constant across the panel
Mitigation: Automated optical inspection of reinforcement materials and statistical process control

Industrial Ecosystem

Compatible With

Typical Suppliers & Equivalents

Compliance & Inspection

Tolerance

Thickness: ±10%, Dielectric constant: ±5%, Dimensional stability: ≤0.1% after lamination

Test Method

IPC-TM-650 test methods for dielectric properties, thermal analysis (TGA/DSC), peel strength testing, and microsection analysis

Procurement Evaluation Criteria

A practical evidence checklist for RFQ preparation and supplier evaluation.

Technical documentation

Request current drawings, revision history, and a signed specification sheet.

Manufacturing capability

Verify equipment lists, process limits, capacity, and representative production evidence.

Inspection readiness

Confirm test methods, calibrated equipment, sampling plans, and traceable reports.

Supplier transparency

Check the legal entity, factory address, ownership, certifications, and direct contacts.

CNFX does not score or rank suppliers. Buyers must verify all claims and documents with the legal manufacturer before ordering.

Manufacturers of Dielectric Core Material

Manufacturer profiles associated with Dielectric Core Material.

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Compiled and source-reviewed by the CNFX editorial team. Each manufacturer above links to the page on that company's own website where the product is listed, with the date we checked it. How we source and review

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Frequently Asked Questions

What is the difference between dielectric core material and prepreg?

Dielectric core material is a fully cured rigid substrate with copper foil on both sides, used as the base layer in PCBs. Prepreg is partially cured resin-impregnated glass fabric that flows during lamination to bond layers together.

How does dielectric constant affect PCB performance?

Lower dielectric constant reduces signal propagation delay and capacitive coupling between traces, enabling higher signal speeds and better impedance control in high-frequency applications.

Can dielectric core materials be used for flexible PCBs?

Standard rigid dielectric cores are not suitable for flex circuits. Flexible PCBs use polyimide or polyester films as dielectric materials instead of glass-reinforced composites.

Data Basis

Editorial classification, named public sources where available, and source-reviewed manufacturer records. See the editorial policy.

Preliminary Technical Classification

This page supports structured research, RFQ preparation, and supplier evaluation. It does not replace buyer-led supplier qualification, standards review, or technical approval.

Dielectric Core Material