Electronic design at the system level consists of integration of an array of different individual semiconductor and electrical components, whether the system is a miniature embedded medical device, or as large as the power electronics driving high-speed passenger trainsets. The integration of so many disparate component types includes ICs, RF devices, power semiconductors, and subassemblies such as DC-DC converters. Many of these component types, while highly efficient, also dissipate some amount of heat. Managing heat dissipation becomes the responsibility of mechanical engineers responsible for the system enclosure, internal mechanical and thermal design, and balancing many competing factors – including industrial design, EMI shielding, airflow and heat flow – while meeting overall system design requirements.
A major failure mechanism for electronic systems is inadequate heat dissipation, both from individual components and at the system level. Heat is the single largest cause of failure, with vibration and dust and other environmental factors as examples of other factors.
Thermal interface materials (TIMs) provide a critical intermediary between processors, power transistors, and other components that generate heat and heat sinks and mechanical components – to allow transfer and spreading of a given heat load to larger metallic surfaces and ultimately to the ambient air. While TIMs are a minor item on the bill of materials for any system, the role that proper evaluation and selection and placement of these materials in production assembly is critical.
This presentation will provide insight on the large number of very different types of TIMs and serve as an overview of several important topics:
• Categorization of TIM types
• Testing methodologies
• Evaluation and selection criteria for implementation
• Continuing challenges and requirements
• Opportunities and recent new developments
There are thousands of interface materials with many different thermal performance values, intended
to address a wide range of requirements across every type of electronic system. Understanding and
devising a logical evaluation of such materials is critically important to system design.