Techniques and mechanisms for providing effective connectivity with surface level microbumps on an integrated circuit package substrate. In an embodiment, different metals are variously electroplated to form a microbump which extends through a surface-level dielectric of a substrate to a seed layer including copper. The microbump includes nickel and tin, wherein the nickel aids in mitigating an absorption of seed layer copper. In another embodiment, the microbump has a mass fraction of tin, or a mass fraction of nickel, that is different in various regions along a height of the microbump.