IEC 61249-2-46:2018

Overview

IEC 61249-2-46:2018 specifies requirements for non-halogenated epoxide non‑woven/woven E‑glass reinforced laminate sheets used in printed boards and other interconnecting structures. The standard covers copper-clad laminate sheets for lead‑free assembly with a defined thermal conductivity of 1.5 W/(m·K) ± 0.2 and a minimum glass transition temperature (Tg) of 105 °C. Applicable laminate thicknesses are 0.60 mm to 1.70 mm. Flammability performance is achieved using non‑halogenated fire retardants chemically reacted into the epoxy matrix and is evaluated by the vertical burning test.

Key topics and technical requirements

• Material construction: Non‑woven core with woven E‑glass surface reinforcements; copper foil cladding suitable for lead‑free processes.
• Thermal performance: Thermal conductivity defined as (1.5 ± 0.2) W/(m·K) (see thermal conductivity table).
• Thermal stability: Minimum Tg = 105 °C; cure factor and decomposition temperature criteria included.
• Flammability: Vertical burning test requirements for defined flame resistance using non‑halogenated retardants.
• Mechanical and dimensional properties: Flexural strength, punching/machining behaviour, bow and twist, thickness tolerances, and dimensional stability.
• Electrical properties: Specified dielectric and conductive performance values for copper‑clad laminates.
• Durability and reliability: Water absorption, measling, time to delamination (TMA), pull‑off and peel strength of copper bond.
• Compliance and quality: Requirements for qualification inspection, quality conformance inspection, certificates of conformance, safety data sheets, packaging and marking, plus ordering information.

(These topics are mapped from the standard’s clauses and tables addressing electrical, non‑electrical, thermal and quality requirements.)

Applications and who uses this standard

IEC 61249-2-46 is intended for manufacturers and users of PCB base materials where:

• High thermal conductivity and lead‑free assembly compatibility are required (e.g., power electronics, LED modules, automotive electronics, telecom and industrial boards).
• Non‑halogenated flammability performance is a regulatory or customer requirement.
• PCB material selection, procurement and specification teams, PCB fabricators, design engineers, and quality/compliance professionals use this standard to verify material conformity and enable reliable manufacturing for high‑temperature lead‑free processes.

Related standards

• Other parts of the IEC 61249 series (Materials for printed boards and other interconnecting structures) provide complementary material specifications and test methods.
• Consult IEC publications and national adoption notes for updates, corrigenda and related normative references referenced in IEC 61249-2-46.

Keywords: IEC 61249-2-46, non-halogenated epoxide, E‑glass reinforced laminate, thermal conductivity 1.5 W/(m·K), copper‑clad, lead‑free assembly, Tg 105 °C, vertical burning test, PCB materials.