Provided is a method of assigning a first set of probe pads to an interposer for maximizing a defect coverage for the interposer. The interposer includes a second set of nets and the defect coverage is based on a ratio between a tested net length and an overall net length. The method includes processing the second set such that every net interconnecting more than two micro-bumps is divided into a plurality of nets and every two of the more than two micro-bumps are interconnected by one of the plurality of nets. The method further includes calculating an untested length of each net in the second set; selecting a first net from the second set with the maximum untested length; selecting two probe pads from the first set based on a user-defined cost function; and connecting the two probe pads to the first net with two dummy nets.