Patent ID: 7768122

Claim:
A semiconductor package comprising: an insulating substrate comprising an element mounting surface; an optical functional element which functions by light irradiation and is mounted on the element mounting surface of the insulating substrate; and a window lid which hermetically seals the element mounting surface and comprises a light transparent member joined to an opening formed thereon, a first flat plate-shaped lid part provided with the opening, and a second frame-shaped lid part which defines an internal cavity of the window lid, wherein the second frame-shaped lid part holds the first lid part by a peripheral edge thereof at a top surface thereof and is joined to the element mounting surface of the substrate on a bottom surface thereof; wherein the insulating substrate comprises; a first heat transfer path which transfers heat from the optical functional element to a back surface of the insulating substrate; a first heat dissipation unit which dissipates the transferred heat by the first transfer path and is attached to the back surface of the insulating substrate and an end of the first heat transfer path, the end being exposed from the insulating substrate; a second heat transfer path which transfers heat from the window lid to a side surface of the insulating substrate; and a second heat dissipation unit which dissipates the transferred heat by the second transfer path and is attached to the side surface of the insulating substrate and an end of the second heat transfer path, the end being exposed from the substrate, and wherein the first and second heat transfer paths comprise respective first and second thermal vias filled with thermal conductive material extending through at least a part of the insulating substrate in a thickness direction, the first thermal via is disposed directly under the optical functional element, and a first portion of the second thermal via extends away from the second frame-shaped lid part of the window lid in the thickness direction of the insulating substrate and a second portion of the second thermal via extends from an end of the first portion of the second thermal via spaced from the second frame-shaped lid part of the window lid to the side surface of the insulating substrate.