US Patent 7307342 Interconnection structure of integrated circuit chip

An interconnection structure includes an integrated circuit (IC) chip having internal circuitry and a terminal to electrically connect the internal circuitry to an external circuit, a passivation layer disposed on a top surface of the IC chip, the passivation layer configured to protect the internal circuitry and to expose the terminal, an input/output (I/O) pad, where the I/O pad includes a first portion in contact with the terminal and a second portion that extends over the passivation layer, and an electroless plating layer disposed on the I/O pad.