A cap layer for a copper interconnect structure formed in a first dielectric layer is provided. The method includes receiving a system configuration signal, the system configuration signal comprising frame configuration information and HARQ delay information, receiving a downlink signal in a DL subframe and transmitting an acknowledgement not-acknowledgement signal for the DL signal in a UL subframe. The lever is pivotally connected to the base and the catch is pivotally connected to the lever.