Integrated Design and Manufacturing of Flat Miniature Heat Pipes Using Printed Circuit Board Technology

A novel, integrated approach in thermal management of electronic products, based on two-phase cooling, is presented. A flat miniature heat pipe, integrated inside the laminated structure of a printed circuit board (PCB) has been developed, based on mainstream PCB fabrication processes. Hot spots on the PCB, caused by heat dissipating components, can be cooled with relatively small temperature gradients across the board. An analytical model is presented to predict the behavior of the embedded heat pipe for various geometries, orientations, and operating temperatures. Experimental verification has shown successful heat pipe operation. The heat pipe exhibited a measured equivalent thermal conductivity more than seven times higher than solid copper. Low-thermal resistance values establish this concept as a promising thermal management solution for future electronic products. As mainstream manufacturing techniques are applied, thin PCBs with integrated cooling support can be produced at low-cost.