ISO 4825-1-2023 PDF

Full title and description

St ISO 4825-1-2023 — Fine ceramics (advanced ceramics, advanced technical ceramics) — Test method for thermal property measurements of metalized ceramic substrates — Part 1: Evaluation of thermal resistance for use in power modules. This standard specifies a laboratory measurement method that evaluates thermal resistance between a heater chip and a cold plate with the heater chip mounted on a metalized ceramic substrate, representing an index of heat-dissipation performance for substrates used in high‑output power modules (for example SiC power modules).

Abstract

This document describes a test procedure to measure the thermal resistance from an active heater element (simulated die) through metallization and ceramic substrate to a cold plate. The measured thermal resistance serves as an indicator of the heat‑dissipation capability of metalized ceramic substrates intended for high‑power electronic modules. The method is intended to provide reproducible, comparable results across laboratories for selection, quality control and R&D of substrate materials and metallization schemes.

General information

• Status: Published.
• Publication date: January 2023 (2023-01).
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 81.060.30 (Advanced ceramics / technical ceramics).
• Edition / version: Edition 1 (2023).
• Number of pages: 12 pages.

Scope

Specifies a laboratory test method for measuring thermal resistance between a heater chip and a cold plate when the heater chip is mounted on a metalized ceramic substrate. The procedure imitates the thermal path of a high‑output power module (e.g., SiC modules) and is intended to quantify heat dissipation characteristics of metallized ceramic substrates for use in design validation, material comparison and manufacturing quality control. The method focuses on the substrate and metallization thermal path rather than the whole packaged module thermal network.

Key topics and requirements

• Definition of test specimen (metalized ceramic substrate) and representative heater (simulated die) mounting.
• Detailed measurement setup: heater, cold‑plate arrangement, mounting pressure/fixture and thermometry.
• Test procedure to determine thermal resistance (K/W) from heater to cold plate and required steady‑state conditions.
• Requirements for sample preparation, metallization geometry and contact/interface control to ensure reproducibility.
• Data reporting items: measured thermal resistance, test conditions, uncertainty considerations and environmental parameters.
• Scope limitations and intended interpretation — method yields an index of substrate heat‑dissipation performance rather than a complete module thermal model.

Typical use and users

Used by power‑electronics engineers, materials scientists, R&D laboratories, test and qualification labs, substrate and metallization manufacturers, and reliability/quality teams in industries developing or qualifying power modules (electric vehicles, traction drives, power converters, renewable energy inverters, industrial drives). Typical applications include material comparison, production quality control, and supporting thermal design choices for high‑power modules.

Related standards

Relevant complementary and precedent guidance includes component/package thermal test methodologies such as the JESD51 series (JEDEC) for junction‑to‑ambient and related thermal measurements, and ASTM test methods commonly used for thermal interface materials (for example ASTM D5470 practices for TIM thermal conductivity testing). Additional parts of the ISO 4825 series addressing other thermal measurement approaches and diagnostic methods are in development (for example an ISO project for Part 6 has been recorded). These documents are commonly used together to build a complete thermal‑characterization and validation program for power modules.

Keywords

Fine ceramics, advanced ceramics, metallized ceramic substrates, thermal resistance, thermal measurement, power modules, SiC modules, heat dissipation, test method, thermal characterization.

FAQ

Q: What is this standard?

A: ISO 4825-1:2023 is an international standard that defines a laboratory test method to measure thermal resistance from a heater chip through a metalized ceramic substrate to a cold plate, producing an index of heat‑dissipation performance for substrates used in high‑power modules.

Q: What does it cover?

A: It covers specimen definition, test setup and instrumentation, the measurement procedure to obtain steady‑state thermal resistance (K/W), sample preparation and reporting requirements. It is scoped to substrate/metallization evaluation rather than modeling an entire packaged module.

Q: Who typically uses it?

A: Power‑electronics designers, substrate and metallization manufacturers, materials and test laboratories, reliability engineers and quality teams—any organization needing reproducible, comparable substrate thermal performance data for design, selection or quality control.

Q: Is it current or superseded?

A: As of its publication, ISO 4825-1:2023 is the current published Part 1 (Edition 1, published January 2023). Users should check for any amendments or revisions after publication for updates.

Q: Is it part of a series?

A: Yes — it is Part 1 of the ISO 4825 series on test methods for thermal property measurements of metalized ceramic substrates. Other parts and technical work items for the ISO 4825 family (covering additional methods and diagnostic procedures) are in development or at project stage.

Q: What are the key keywords?

A: Fine ceramics; advanced ceramics; metalized ceramic substrate; thermal resistance; thermal measurement; power module; SiC; test method; heat dissipation.