Abstract: An electrical connection structure is provided. The electrical connection structure includes a through hole, a first pad, a second pad and a conductive bridge. The through hole has a first end and a second end. The first pad at least partially surrounds the first end of the through hole and is electrically connected to a first circuit. The second pad is located at the second end of the through hole and is electrically connected to a second circuit. The conductive bridge is connected to the first pad and second pad through the through hole, thereby making the first and second circuits electrically connected to each other.

Abstract: The present invention relates to a data transferring method for a multicast system. The multicast system includes a server, a switch and clients. First, the server creates a multicast group and broadcasts the data blocks of a data series sequentially and repeatedly. When clients would like to download the data series from the server in different instances, they join the same multicast group and receive the data blocks from the data block that the server is currently broadcasting. At the same time, the clients also generate a receiving history regarding the data block first received. The clients can determine when to stop receiving the data blocks based on the receiving history.