Low-stress vias
A component can include a substrate having a front surface and a rear surface remote therefrom, an opening extending from the rear surface towards the front surface, and a conductive via extending within the opening. The substrate can have a CTE less than 10 ppm/° C. The opening can define an inner surface between the front and rear surfaces. The conductive via can include a first metal layer overlying the inner surface and a second metal region overlying the first metal layer and electrically coupled to the first metal layer. The second metal region can have a CTE greater than a CTE of the first metal layer. The conductive via can have an effective CTE across a diameter of the conductive via that is less than 80% of the CTE of the second metal region.
1. A component, comprising:
a substrate having a front surface and a rear surface remote therefrom, the substrate consisting essentially of a material having a coefficient of thermal expansion (CTE) less than 10 ppm/° C.;
an opening extending from the rear surface towards the front surface through the material, the opening defining an inner surface between the front and rear surfaces; and
a conductive via extending within the opening, the conductive via including a metal region overlying the inner surface and having a plurality of cavities trapped therein,
wherein one or more axially facing regions of the metal region include a boundary material deposited into a subset of the cavities within the metal region, the boundary material extending to a depth below the respective front or rear surface.
2. The component as claimed in claim 1 , wherein the conductive via also includes a barrier metal layer between the metal region and the inner surface, the barrier metal layer being a metal different than the metal of the metal region.
3. The component as claimed in claim 2 , wherein the metal region is a first metal region and the barrier metal layer is a first barrier metal layer, wherein the conductive via also includes a second metal layer overlying the first barrier metal layer and a third barrier metal layer between the first metal region and the second metal layer.
4. The component as claimed in claim 1 , wherein the trapped cavities have an average diameter greater than 1 micron.
5. The component as claimed in claim 1 , further comprising a conductive contact exposed at the rear surface for interconnection with an external element, the conductive contact being electrically connected with the metal region.
6. The component as claimed in claim 1 , further comprising an insulating dielectric layer coating the inner surface defined by the opening, the dielectric layer separating and insulating the conductive via from the substrate at least within the opening.
7. The component as claimed in claim 1 , wherein the boundary material includes solder.
8. The component as claimed in claim 1 , wherein the boundary material includes a polymer medium.
9. The component as claimed in claim 1 , wherein the metal region has a dendritic metal structure.
10. A system comprising a structure according to claim 1 and one or more other electronic components electrically connected to the structure.
11. The system as claimed in claim 10 , further comprising a housing, said structure and said other electronic components being mounted to said housing.
12. A component, comprising:
a substrate having a front surface and a rear surface remote therefrom, the substrate consisting essentially of a material having a coefficient of thermal expansion (CTE) less than 10 ppm/° C.;
an opening extending from the rear surface towards the front surface through the material, the opening defining an inner surface between the front and rear surfaces; and
a conductive via extending within the opening, the conductive via including a metal region overlying the inner surface and having a plurality of cavities trapped therein,
wherein the substrate has a transition surface between the opening and at least one of the front or rear surfaces, wherein a radius of the transition surface is greater than 5% of a radius of the opening.
13. The component as claimed in claim 12 , wherein the conductive via also includes a barrier metal layer between the metal region and the inner surface, the barrier metal layer being a metal different than the metal of the metal region.
14. The component as claimed in claim 13 , wherein the metal region is a first metal region and the barrier metal layer is a first barrier metal layer, wherein the conductive via also includes a second metal layer overlying the first barrier metal layer and a third barrier metal layer between the first metal region and the second metal layer.
15. The component as claimed in claim 12 , wherein the trapped cavities have an average diameter greater than 1 micron.
16. The component as claimed in claim 12 , further comprising a conductive contact exposed at the rear surface for interconnection with an external element, the conductive contact being electrically connected with the metal region.
17. The component as claimed in claim 12 , further comprising an insulating dielectric layer coating the inner surface defined by the opening, the dielectric layer separating and insulating the conductive via from the substrate at least within the opening.
18. A system comprising a structure according to claim 12 and one or more other electronic components electrically connected to the structure.
19. The system as claimed in claim 18 , further comprising a housing, said structure and said other electronic components being mounted to said housing.