Optimal signal routing performance through dielectric material configuration designs in package substrate

Abstract

Embodiments include package substrates and methods of forming the package substrates. A package substrate includes a first conductive layer in a first dielectric, a second dielectric over the first dielectric, and a second conductive layer in the second dielectric, where the second conductive layer includes first and second traces. The package substrate also includes a third conductive layer over the second dielectric, and a high dielectric constant (Dk) and low DK regions in the first and second dielectrics, where the high Dk region surrounds the first traces, and where the low Dk region surrounds the second traces. The high Dk region may be between the first and third conductive layers. The low Dk region may be between the first and third conductive layers. The package substrate may include a dielectric region in the first and second dielectrics, where the dielectric region separates the high Dk and low Dk regions.