An electronic device comprising: a substrate including a metal trace electrically connected to a ground plane ; and a system in package assembly comprising: a plurality of components , the plurality of components including a first component and a second component , each component including a first surface mounted to the substrate and a second surface; a first thermal plug mounted to the second surface of the first component, wherein a first surface of the first thermal plug is attached to the second surface of the first component, and the first thermal plug is a same size as the first component; an electrically insulating layer disposed around the plurality of components and the first thermal plug; a trench formed through the electrically insulating layer between the first component and the second component and exposing the metal trace ; and a shielding layer spanning within the trench, over the insulating layer, and touching the second surface of the first thermal plug, wherein the shielding layer within the trench contacts the metal trace of the substrate to dissipate and spread heat from the first thermal plug to the substrate and electrically connect the shielding layer and the first thermal plug to the ground plane . a substrate including a metal trace electrically connected to a ground plane ; and a system in package assembly comprising: a plurality of components , the plurality of components including a first component and a second component , each component including a first surface mounted to the substrate and a second surface; a first thermal plug mounted to the second surface of the first component, wherein a first surface of the first thermal plug is attached to the second surface of the first component, and the first thermal plug is a same size as the first component; an electrically insulating layer disposed around the plurality of components and the first thermal plug; a trench formed through the electrically insulating layer between the first component and the second component and exposing the metal trace ; and a shielding layer spanning within the trench, over the insulating layer, and touching the second surface of the first thermal plug, wherein the shielding layer within the trench contacts the metal trace of the substrate to dissipate and spread heat from the first thermal plug to the substrate and electrically connect the shielding layer and the first thermal plug to the ground plane . a plurality of components , the plurality of components including a first component and a second component , each component including a first surface mounted to the substrate and a second surface; a first thermal plug mounted to the second surface of the first component, wherein a first surface of the first thermal plug is attached to the second surface of the first component, and the first thermal plug is a same size as the first component; an electrically insulating layer disposed around the plurality of components and the first thermal plug; a trench formed through the electrically insulating layer between the first component and the second component and exposing the metal trace ; and a shielding layer spanning within the trench, over the insulating layer, and touching the second surface of the first thermal plug, wherein the shielding layer within the trench contacts the metal trace of the substrate to dissipate and spread heat from the first thermal plug to the substrate and electrically connect the shielding layer and the first thermal plug to the ground plane . <EOS>