Electronic assemblies without solder and methods for their manufacture

The present invention provides an electronic assembly 400 and a method for its manufacture 800, 900, 1000 1200, 1400, 1500, 1600, 1700. The assembly 400 uses no solder. Components 406, or component packages 402, 802, 804, 806 with I/O leads 412 are placed 800 onto a planar substrate 808. The assembly is encapsulated 900 with electrically insulating material 908 with vias 420, 1002 formed or drilled 1000 through the substrate 808 to the components' leads 412. Then the assembly is plated 1200 and the encapsulation and drilling process 1500 repeated to build up desired layers 422, 1502, 1702. Assemblies may be mated 1800. Within the mated assemblies, items may be inserted including pins 2202a, 2202b, and 2202c, mezzanine interconnection devices 2204, heat spreaders 2402, and combination heatspreaders and heat sinks 2602. Edge card connectors 2802 may be attached to the mated assemblies.