Electrical components in an electronic device are mounted on substrates such as printed circuits. Printed circuits contain signal paths formed from metal traces. The signal lines in the signal paths of the printed circuits are coupled together using electrical connection structures such as printed circuit board-to-board connectors, contacts joined by anisotropic conductive film, or contacts joined using solder. Electrical connection structures may be surrounded by conductive resilient ring-shaped structures such as conductive foam structures or spring structures. The conductive foam structures may be provided with a metal layer with which the conductive foam structures are soldered to a ring of metal on a printed circuit. Strain relief structures may be formed from an elastomeric ring that surrounds the electrical connection structures or an overmolded plastic structure. Coating layers and conductive plastic may be used in providing strain relief structures with electromagnetic interference shielding capabilities.