A method to produce a substrate suitable for diffusion bonding is described. A flexible dielectric substrate is provided. An alkaline modification is applied to the dielectric substrrate to form a polyamic acid (PAA) anchoring layer on a surface of the dielectric substrate. A Ni-P seed layer is elecrolessly plated on the PAA layer. Copper traces are plated within a photoresist pattern on the Ni-P seed layer. A surface finishing layer is electrolytically plated on the copper traces. The photoresist pattern and Ni-P seed layer not covered by the copper traces are removed to complete the substrate suitable for diffusion bonding.