Computer board with dual shield housing and heat sink expansion zone apparatuses

A compact computer system board comprises dual on PCB expansion zones , expansion connectors which can be connected to expansion boards. Once a expansion board is connected to the expansion connector in the on PCB expansion zone to extent the application of the system , a metal housing cover will be mounted above the on PCB expansion zone. The shield expansion apparatus formed by on PCB expansion zone and metallic housing cover isolates the electromagnetic interference between add-on expansion daughter card and the environment outside of the shield expansion apparatus. The metal housing cover as well as the on PCB expansion zone function as the heat sink of the add-on expansion daughter card inside the apparatus. Dual complete EMI shield expansion apparatuses especially eliminate the cross interference and provide high heat dispassion for the system under the situation when there are two radio frequency application expansion boards installed onto the system board.