Design And Application Considerations Of Packaging Of Dc-Dc Converter Micromodules

This paper presents different design considerations of two different packaging approaches for micromodules, namely vertically integrated ferrite substrate based [1] and conventional overmolded side-by-side integration [2]. Production steps, EMI, and thermal considerations are covered in this paper. Two dc-dc converter micromodules with the same specifications are built using both packaging approaches and tested. The vertically integrated micromodule has dimensions of 3.2 X 2.5 X 1.6mm(3) while the side-by-side integrated micromodule achieves 2.5 X 2.5 X 1.2mm(3) dimensions. Both modules achieve peak efficiency of 87% for 5Vin-to-1.8V out conversion. Experimental evaluation and market requirements suggest the suitability of vertically integrated micromodule for applications, which require very low noise level (radiated emissions) and excellent thermal derating performance such as data acquisition and measurements. On the other hand, side-by-side integrated micromodules are suitable for applications that require low profile height and have aggressive cost requirements such as consumer electronics, i.e. tablets, smart phones, and laptops.