Decreasing LED Heat Sink Weights by 27% with Generative Design

As LED chip costs have significantly decreased over the last decade, LED light manufacturers' focus has shifted to optimizing light fixtures instead, the primary cost driver in LED systems. The Brazilian thermal management bureau, Celera, successfully used ColdStream to generate a new heat sink design whose weight decreased by 27% without any significant increase in temperature, enabling their customers to save considerable manufacturing costs. The challenge lay in reducing fixture weight to lower material and manufacturing costs and environmental impacts while maintaining thermal performance and reliability. Given that traditional design methods are ill-suited for design generation due to their long cycle times, Celera decided to use generative design to quickly generate a high number of possible designs and test them.

Generative design’s core advantages included:

• Accelerating the design process through automation.
• Eliminating human bias in design exploration.
• Producing lightweight, efficient designs that maintained performance standards.

Process

Using topology optimization, generative design redistributed material within the design space, testing and refining different solutions to achieve an optimal outcome, balancing weight reduction with thermal efficiency. The design process began with defining the design space, as engineers created an initial CAD model to establish the necessary geometry. Next, they incorporated material properties, heat loads, and ambient conditions into the platform to ensure an accurate representation of real-world behavior. This allowed the software to iterate through different design possibilities quickly and automatically, continuously evaluating and improving the designs until achieving the ideal balance between performance and material efficiency.

Results

The original design showed a standard heat sink weighing 6.143 kg with a maximum junction temperature of 80°C. It was compared to two additional designs created by ColdStream based on two different approaches.

1. Generative Design Approach: ColdStream was given free rein to find a suitable design with minimal human input. This design achieved a 16.4% reduction in weight with a slight temperature increase of 4.4°C.
2. Hybrid Optimization: This approach combined generative design with human expertise, resulting in a 27.6% weight reduction down to 4.453 kg while maintaining safe thermal performance below the junction temperature limit of 120°C.

These results demonstrated that even a modest increase in junction temperature could unlock significant material savings, translating to cost and environmental benefits.

Conclusion

The use of generative design for thermal performance was a success, as it led to a significant weight reduction without any significant temperature increase, enabling a reduction in raw material use, environmental impact, and manufacturing and transport costs. This case study underscores the relevance of generative design in empowering manufacturers to strike a balance between performance and sustainability, fueling innovation in an industry increasingly focused on environmentally friendly solutions.

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