Advances in power-module packaging technology have enabled increasingly robust, small, and easy-to-use DC/DC solutions. Power modules integrate a DC/DC converter integrated circuit (IC) with passive components in one compact package to simplify the design process and accelerate time to market.There are now several different module package options on the market – embedded, leaded and quad flat no-lead (QFN) – each with their own benefits and drawbacks. Here's a quick comparison:
Embedded modules such as the TPS82150 offer the smallest total solution size available of all module packages. A printed circuit board (PCB) serves as the base of the module, and as the name implies, the converter IC is embedded directly within the PCB. This frees up space on the top of the board for passive components,
Leaded modules such as the LMZ14203 are the easiest to use of all of the module packages, as they provide the same benefits engineers have come to expect from leaded ICs. Leaded modules are manufactured by attaching the die to the underside of the top lead frame, which is then mated to the top of the bottom lead frame. The bottom lead frame serves as a base for the module, and has
a large exposed pad that enables the module to dissipate heat effectively during operation. The inductor and resistors are placed on the top side of the top lead frame, which is molded with epoxy to encapsulate the components while leaving the leads exposed.
QFN modules such as the TPSM84A22 offer the highest density of all module package options. There are three slightly different approaches to manufacturing QFN modules: overmolded lead frame, overmolded laminate and open frame laminate. Regardless of manufacturing technique, QFN modules are unique in that they use pre-packaged, tested silicon rather than unpackaged die and have a footprint similar to QFN ICs. QFN modules’ higher current density enables the powering of applications that other modules can’t touch, such as high-end field-programmable gate arrays (FPGAs)
For more information on these different types of power modules, regarding their module size, component integration, thermal performance and electromagnetic interference (EMI) considerations, please down "Benefits and trade-offs of various power-module package options" by Texas Instruments by clicking here.