Multi-layer, multi-material fabrication methods for producing micro-scale and millimeter-scale devices with enhanced electrical and/or mechanical properties

Abstract

Some embodiments of the invention are directed to electrochemical fabrication methods for forming structures or devices (e.g. microprobes for use in die level testing of semiconductor devices) from a core material and a shell or coating material that partially coats the surface of the structure. Other embodiments are directed to electrochemical fabrication methods for producing structures or devices (e.g. microprobes) from a core material and a shell or coating material that completely coats the surface of each layer from which the probe is formed including interlayer regions. Additional embodiments of the invention are directed to electrochemical fabrication methods for forming structures or devices (e.g. microprobes) from a core material and a shell or coating material wherein the coating material is located around each layer of the structure without locating the coating material in inter-layer regions. Each of these groups of embodiments incorporate both the core material and the coating material during the formation of each layer and each layer is also formed with a sacrificial material that is removed after formation of all layers of the structure. In some embodiments the core material may be a genuine structural material while in others it may be only a functional structural material (i.e. a material that would be removed with sacrificial material if it were accessible by an etchant during removal of sacrificial material.