TWI Industrial Member Report Summary 923/2009
By C Otter, H Goddin, R Saraswat, S Smith, A Bahrami and V Dorbais
Background
An important recent industrial advance has been the development of compact electronic modules for power-control, high speed processing, and operation in extreme environments. These electronic modules experience high thermal loads, either generated internally by self heating, eg power-controlling transistors, or externally, eg by proximity to engines.
Thermal management is the term used to describe the design process and constructions used to extract and dissipate heat from modules and protect them from extremes of temperature. It has emerged as a critical technology for reliability of electronic systems. Many of the technologies used are mature and are often the size limiting factor for electronic modules, so new technologies and methods of validation are being sought.
The multitude of interfaces between materials and components increase the difficulties in modelling the performance of a thermal management solution. So for validation the development of practical and non-disruptive temperature measurements on live electronics is essential. Systems eventually dissipate the thermal load into the ambient, most often to air, and since this is an especially difficult and critical interface it is necessary to develop controlled measurement techniques, such as a micro wind tunnel.
A number of significant TWI technologies and capabilities have contributed to this project, including Surfi-sculptTM, numerical modelling, carbon nanotubes and direct metal to ceramic bonding, the culmination of which was the building and testing of a variety of heat sink cooled assemblies.
Objectives
- Develop a wind tunnel facility for thermal management assessment of materials and assemblies.
- Assess novel materials and methods for device/circuit cooling.
- Develop computational fluid dynamics models for the assessment of Surfi-sculpt heat sink performance.
- Review state-of-the-art for solder and adhesive materials for power electronics manufacture.