A High Power Density Thermal Management Approach Using Multi-PCB Distributed Cooling (MPDC) Structure

This paper presents a new thermomechanical PCB design that uses a multi-PCB cooling (MPDC) structure to achieve higher power density while maintaining thermal performance. The new MPDC structure focusses on three design principles: multiple vertically stacked PCB's for more efficient use of space, component sorting based on losses for improved cooling, and integrated liquid cooling for maximum thermal dissipation. Liquid cooling method is utilized to implement the thermal management problem with very high power density. Finite element analysis (FEA) based thermal analysis was conducted on the 1.3kW converter with two-PCB integrated liquid cooling model. Same thermal estimation as single PCB structure was verified. An experimental prototype with one PCB and cooling setup with liquid and air cooling was built. A 1.3 kW LLC power converter was developed, 50% less temperature rise on critical devices and 0.6% better efficiency are achieved. Thereafter, the proposed MPDC structure was investigated based the single PCB design. The two-layer MPDC prototype repeats the same efficiency and thermal performance while achieving 31% improvement in power density.