IEC 61189-2-808:2024 PDF

Overview

IEC 61189-2-808:2024 is an international standard developed by the International Electrotechnical Commission (IEC) that specifies a test method for characterizing the thermal resistance of an assembly using the thermal transient method. This method is designed for electrical materials, printed boards, and other interconnection structures and assemblies. The purpose is to measure the thermal resistance of assemblies composed of a heat source (such as a power device), an attachment material (such as solder), and a dielectric layer with electrode. The thermal transient method provides a practical approach for evaluating both the materials and the assembly processes used in electronic packaging, aiming to enhance heat dissipation and optimize thermal management in electronic systems.

Key Topics

• Thermal Resistance Measurement: The standard outlines procedures to determine the thermal resistance of an assembly, rather than of the dielectric material alone.
• Thermal Transient Method: This method evaluates the transient thermal behavior of a test assembly, offering insights into the heat transfer effectiveness of various materials and attachment methods.
• Assembly Components: Focus on heat sources, solder or other attachment materials, dielectric substrates, electrodes, and the use of thermal interface materials (TIMs).
• Test Equipment and Procedures:
  • Use of thermal transient test equipment, typically computer-controlled, to apply programmed thermal excitations.
  • Measurement of cooling curves and extraction of key resistance values using standardized parameters.
• Evaluation and Reporting:
  • Structure and preparation of test specimens.
  • Recording and analysis of thermal transients with and without TIMs.
  • Clear guidelines for reporting results, including the structure, materials, test conditions, and data analysis processes.

Applications

IEC 61189-2-808:2024 has broad applications in sectors requiring effective thermal management of electronics, including:

• Printed Circuit Board (PCB) Manufacturing: Evaluation and optimization of PCB materials and assembly processes to ensure efficient heat dissipation.
• Power Electronics: Testing thermal pathways in power devices, LEDs, and high-power semiconductors, where managing junction temperature is critical for reliability.
• Quality Assurance and R&D: Comparing different attachment techniques (solders, adhesives) and their impact on the assembly's thermal resistance.
• Thermal Management Solutions: Validation and selection of thermal interface materials for assemblies, optimizing the design for superior thermal flux to heat sinks.
• Performance Benchmarking: Establishing baseline measurements for electronic packages to meet international compliance and reliability standards.

Related Standards

While IEC 61189-2-808 specifically addresses the methodology for measuring assembly-level thermal resistance, several other standards cover related aspects:

• IEC 60194-2: Vocabulary for printed board and electronic assembly technologies.
• JEDEC JESD51 Series: A suite of standards for thermal measurement methods for semiconductor devices and LED packages, including dual-interface and electrical test methods.
• ASTM C1113, E1461, D5470: Standards for measuring thermal conductivity and resistance properties of materials, referenced for dielectric material testing.

Note: IEC 61189-2-808 is not intended for standalone measurement of dielectric material thermal resistance. For such purposes, refer to the ASTM standards above and their equivalents.

Practical Value

Adoption of IEC 61189-2-808:2024 helps ensure the reliability, safety, and efficiency of electronic assemblies through robust characterization of thermal paths. Implementing its procedures supports:

• Better control of heat dissipation in densely packed and high-power electronic devices.
• Enhanced product lifetime by preventing overheating.
• Regulatory compliance and competitive differentiation in global electronics markets.

By following this standard, engineers and manufacturers can systematically assess and optimize heat transfer within their products, leading to higher-performing and more reliable devices in the field.