IEC 61249-2-45:2018

Overview

IEC 61249-2-45:2018 specifies requirements for non‑halogenated epoxide non‑woven/woven E‑glass reinforced laminate sheets that are copper‑clad for lead‑free assembly. The standard covers clad and unclad reinforced base materials with specified thermal conductivity of (1,0 ± 0,15) W/(m•K), defined flammability (vertical burning test), and a minimum glass transition temperature (Tg) of 105 °C. Applicable thicknesses are 0.60 mm to 1.70 mm. Flammability performance is obtained by non‑halogenated fire retardants chemically reacted into the epoxide polymer.

Key topics and technical requirements

The standard defines material, construction and performance requirements for PCB laminate sheets, including:

• Resin system: non‑halogenated epoxide with reactive fire retardants (integral to polymer structure).
• Reinforcement: non‑woven core and woven E‑glass surface reinforcements.
• Thermal properties: thermal conductivity specified at 1,0 W/(m•K) ±0.15; Tg ≥ 105 °C.
• Flammability: vertical burning test requirements and criteria for achieving a defined flammability rating.
• Mechanical and dimensional properties: laminate thickness tolerances (0.60–1.70 mm), bow and twist, flexural strength, time‑to‑delamination, water absorption and measling.
• Copper foil and bonding: requirements for metal foil, copper‑to‑laminate bond strength (peel/pull‑off), and surface appearance.
• Electrical properties: dielectric and insulation characteristics relevant to interconnecting structures.
• Quality and conformity: qualification inspection, conformance testing, certificates of conformance, safety data sheets, packaging and marking.

(IEC 61249‑2‑45 organizes these into normative tables and test methods to ensure consistent procurement and manufacture.)

Applications and practical value

IEC 61249‑2‑45 targets PCB materials where higher thermal conductivity and controlled flammability are required while maintaining lead‑free assembly compatibility. Common applications include:

• Power electronics and power distribution boards where heat dissipation is critical.
• Automotive, industrial and telecom PCBs exposed to elevated temperatures and strict flammability constraints.
• High‑reliability consumer or medical electronics needing non‑halogenated materials for reduced corrosive residues.
• OEMs and PCB fabricators specifying materials for lead‑free reflow and assembly processes.

Using this standard helps procurement, material suppliers and PCB manufacturers ensure materials meet thermal, mechanical and safety expectations for end‑use applications.

Who should use this standard

• PCB laminate manufacturers and material formulators
• PCB fabricators and assemblers (lead‑free processes)
• Design engineers and thermal management specialists
• Quality, compliance and procurement teams specifying board materials

Related standards

• Other parts of the IEC 61249 series on materials for printed boards and interconnecting structures.
• Industry PCB material and assembly standards used in conjunction with IEC 61249‑2‑45 for full qualification and acceptance testing.