Silicon chip carrier with conductive through-vias and method for fabricating same
View Patent ↗A carrier structure and method for fabricating a carrier structure with through-vias each having a conductive structure with an effective coefficient of thermal expansion which is less than or closely matched to that of the substrate, and having an effective elastic modulus value which is less than or closely matches that of the substrate. The conductive structure may include concentric via fill areas having differing materials disposed concentrically therein, a core of the substrate material surrounded by an annular ring of conductive material, a core of CTE-matched non-conductive material surrounded by an annular ring of conductive material, a conductive via having an inner void with low CTE, or a full fill of a conductive composite material such as a metal-ceramic paste which has been sintered or fused.
1. A semiconductor carrier structure for mounting semiconductor chips comprising:
a semiconductor substrate comprising a substrate material having a first coefficient of thermal expansion and a first elastic modulus;
at least one constant diameter through-via in said semiconductor substrate, wherein each of said through-vias is filled with a conductive structure having a second coefficient of thermal expansion which is less than or substantially the same as the first coefficient of thermal expansion and a second elastic modulus which is less than or equal to the first elastic modulus, wherein said each conductive structure comprises a first conductive via material disposed in annular shape along the sidewalls of said through-via, said annular shape having an annular diameter which is said constant diameter and having a core structure comprising a second via material disposed within said annular shape and having a core diameter which is less than said constant diameter.
2. The semiconductor carrier structure of claim 1 wherein said second via material comprises an insulating material.
3. The semiconductor carrier structure of claim 1 wherein said second via material comprises a conducting material.
4. The semiconductor carrier structure of claim 1 wherein said second via material comprises said substrate material.
5. The semiconductor carrier structure of claim 1 wherein said second via material is selected from the group consisting of polyimide, thermid, KJ, photosensitive polyimide, SiLK, or other high-temperature polymer.
6. The semiconductor carrier structure of claim 1 wherein said second via material comprises a material having a third coefficient of thermal expansion which is less than or about equal to said first coefficient of thermal expansion.
7. The semiconductor carrier structure of claim 1 wherein said second via material comprises silicate glass.
8. The semiconductor carrier structure of claim 1 wherein said second via material comprises of silica or a silicate glass-filled high temperature polymer.