A microelectronic system may include a microelectronic component having electrically conductive elements exposed at a first surface thereof, a socket mounted to a first surface of the microelectronic component and including a substrate embedded therein, one or more microelectronic elements each having active semiconductor devices therein and each having element contacts exposed at a front face thereof, and a plurality of socket pins mounted to and extending above the substrate, the socket pins being ground shielded coaxial socket pins. The one or more microelectronic elements may be disposed at least partially within a recess defined within the socket. The socket may have a land grid array comprising top surfaces of the plurality of the socket pins or electrically conductive pads mounted to corresponding ones of the socket pins, and the element contacts of the one or more microelectronic elements may be pressed into contact with the land grid array.

Assemblies and methods of manufacturing assemblies that include sockets and packaged semiconductor chips are provided. The package substrates for the semiconductor chips can include cores that are formed from a solid amorphous glass layer. The package substrates can have gaps around sides and alignment pins in the assemblies.

A differential transmission board set includes a mounting board on which a compression connector is mounted and a contact board configured to come into contact with the compression connector. In the contact board, a second conductor layer is a ground layer and has a penetrating hole. The penetrating hole is formed in such a way that a first signal pad and a second signal pad are both located inside an inner edge of the penetrating hole. In the contact board, the penetrating hole is formed to overlap an outer region of the first ground pad and an outer region of the second ground pad.