IEC TS 62788-2:2017

Overview

IEC TS 62788-2:2017 - Measurement procedures for materials used in photovoltaic modules, Part 2: Polymeric materials – Frontsheets and backsheets - defines standardized test methods and datasheet reporting for non‑rigid polymeric materials used as frontsheets and backsheets in terrestrial photovoltaic (PV) modules. The technical specification describes how to characterize mechanical, electrical, thermal, optical and chemical properties in ways that are representative of actual module construction and service conditions. It supports PV module safety and performance testing at the module level (see IEC 61730 and IEC 61215).

Key Topics

The standard provides procedures and reporting requirements for:

• Mechanical characteristics: thickness, area weight, tensile strength, elongation, curling.
• Adhesion testing: 180° peel, T‑peel, dynamic pluck, lap‑shear, cross‑hatch tape tests and related specimen preparation and conditioning.
• Thermal properties: thermal endurance, dimensional stability, coefficient of thermal expansion (CTE), thermal conductivity.
• Electrical properties: DC breakdown voltage, distance through insulation (dti), Comparative Tracking Index (CTI), volume resistivity.
• Optical properties: optical transmittance (frontsheets), reflectance (backsheets), yellowness index (YI), colour (L*, a*, b*), surface gloss.
• Diffusion and barrier performance: water vapour and oxygen permeability.
• Chemical resistance and other characteristics (ignitability, flammability).
• Accelerated ageing tests: damp heat, weathering and other accelerated exposure protocols.
• Data reporting: uniform characterization form (UCF), material datasheet and product identification/label requirements.

Keywords integrated: IEC TS 62788-2:2017, polymeric backsheets, polymeric frontsheets, PV module materials, test methods, datasheet reporting.

Applications

IEC TS 62788-2:2017 is intended for:

• PV module manufacturers validating material compatibility and module construction.
• Material and film suppliers qualifying polymeric frontsheets/backsheets for PV use.
• Independent test laboratories performing standardized mechanical, electrical, thermal, optical and barrier tests.
• Certification bodies and quality assurance teams aligning material-level tests with module-level standards (IEC 61730 / IEC 61215).
• R&D teams developing new polymeric formulations and laminate stacks for improved durability and safety.

Practical uses include material selection, failure analysis, lifetime prediction, vendor comparison, and compliance documentation.

Related standards

• IEC 61730 - PV module safety qualification (supported by material tests in this TS)
• IEC 61215 - PV module performance qualification (material-level methods here support module‑level tests)

IEC TS 62788-2:2017 provides a consistent, application‑focused framework to measure and report polymeric material properties crucial to PV module durability, safety and long‑term performance.