ISO/NP 4825-6

Fine ceramics (advanced ceramics, advanced technical ceramics) — Test method for thermal property measurements of metalized ceramic substrates — Part 6: Method for Locating Degradation of Components and Connection Points in Power Modules with Transient Thermal Network Model

Scope

This document specifies a test method for locating degradation points of metallised ceramic substrates inside power module packages using a transient thermal network model. The method provides standardized measurement procedures to detect degradation in components, bonding interfaces, and metallised ceramic substrates, including ceramic plates and their metallisation bonding layers. By enabling clear and reproducible evaluation of thermal response changes, the test method supports reliable assessment of module quality, comparability of results among laboratories, and long-term reliability assurance for industrial applications where power modules are expected to operate over lifetimes that span decades.
This document:
- applicable to modules incorporating Insulated Gate Bipolar Transistors (IGBTs) with anti-parallel diodes, reverse-conductive (RC) IGBTs, MOSFETs with body diodes, or external free-wheeling diodes;
- focuses on modules assembled with metallised ceramic substrates for wiring, electrical insulation and thermal conduction;
- covers test environment conditions, equipment requirements, measurement procedures, calculation methods, and evaluation criteria for identifying degradation sites;
- does not cover the design or specification of proprietary measurement instruments.