Interposer defect coverage metric and method to maximize the same

摘要

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.

主权项

1. A method of assigning a first set of probe pads to an interposer for maximizing a defect coverage for the interposer, wherein the interposer includes a second set of nets interconnecting a plurality of micro-bumps and the defect coverage is based on a ratio between a tested net length and an overall net length, comprising the steps of:
calculating the overall net length by summing up a length of each net in the second set; for each net T in the second set that interconnects more than two micro-bumps, replacing T with a plurality of nets such that each of the plurality of nets is a portion of T and connects only two of the more than two micro-bumps, and every two of the more than two micro-bumps are interconnected by one of the plurality of nets; 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, wherein at least one of: the calculating of the overall net length, the replacing of T with the plurality of nets, the calculating of the untested length, the selecting of the first net, the selecting of the two probe pads, and the connecting of the two probe pads is performed by a computing system.