Does the Thermal Pad located on the bottom of the device need to be electrically connected to the PWB?
In my design, there is only one ground - what I call "Common GND" in this discussion. I have all the device GND and PGND pins connected to the card Common GND right at the device. Soldering the thermal Pad under the device requires special techniques such as wave soldering and is difficult. I can easily put a thin thermal interface between the Thermal Pad and the PWB to remove the heat from the device, but the thin thermal interface is not electrically conductive. This thin thermal interface has been modeled and is sufficient to get out the heat. Is there an electrical reason that that the Thermal Pad must be electrically connected to Common GND on the PWB since all the PGND and GND pins are connected?
