Patent ID: 8309973
Filing Date: 2012-11-13
Classification: H01L

Abstract:
1. A sub-mount for an optoelectronic device comprising: a silicon substrate having a thickness in the range of 350 μm-700 μm and having a front-side surface and a back-side surface; a singular die attach pad on which to mount the optoelectronic device, the die attach pad disposed on the front-side surface of the substrate; a front side via structure having a first bottom and inclined walls such that a cross-section of the front side via structure becomes increasingly narrower from the front-side surface toward the back-side surface; a back side via structure having a second bottom and inclined walls such that a cross-section of the back side via structure becomes increasingly narrower from the back-side surface toward the front-side surface, wherein the first bottom and the second bottom are not a same size, and wherein the first bottom and the second bottom meet between the front-side surface and the back-side surface; an insulating layer over the inclined walls of the back side via structure; feed-through metallization over the insulating layers in the back side via structure; a first contact pad disposed on the front-side surface of the substrate and directly electrically contacted at the front-side surface of the substrate to the die attach pad; and a second contact pad disposed on the front-side surface of the substrate and not directly electrically contacted at the front-side surface to the die attach pad, wherein the feed-through metallization in at least one of the via structures electrically couples the die attach pad to a first surface mount device (“SMD”) pad on the back-side surface of the substrate.