Non-planar interface construction

A cutting element is provided, including a substrate and an ultra-hard material layer formed over the substrate. At one end of the substrate is an interface surface that interfaces with the ultra-hard material layer to bond the layer to the substrate. The interface surface includes a first or outer annular section that extends to the peripheral edge of the substrate, and a second or inner section that is radially inside the first section. The interface surface includes several spaced-apart projections arranged in an annular row. In one aspect, each projection has an upper surface that defines a groove bisecting the projection. In another aspect, the interface surface may include a bridge coupling adjacent projections.