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.