Patent ID: 9553065
Date: 2017-01-24
CPC Classifications: H01L

Claim:
1. A device comprising: a semiconductor die comprising a substrate, electrical circuits formed along a first side of the substrate and a redistribution layer over the first side of the substrate; a plurality of under bump metal structures arranged in rows and columns on a center region of a top surface of the substrate; a first under bump metal structure formed in a first region of the semiconductor die, wherein the first under bump metal structure is of a first diameter and a bottom of the first under bump metal structure is in direct contact with the redistribution layer, and wherein the first under bump metal structure is electrically connected to the electrical circuits through a first metal line in a bottom metallization layer, a second metal line in a top metallization layer, a via in a passivation layer, an aluminum pad in a first polymer layer and the redistribution layer; a second under bump metal structure formed in a second region of the semiconductor die, wherein the second under bump metal structure is of a second diameter and a bottom of the second under bump metal structure is in direct contact with the redistribution layer, and wherein the second under bump metal structure and the first under bump metal structure are immediately adjacent to each other; a third under bump metal structure having a third diameter formed in the second region of the semiconductor die, wherein the second under bump metal structure and the third under bump metal structure are in a same row and immediately adjacent to each other, and wherein the third diameter is equal to the second diameter and the first diameter is greater than the second diameter; a fourth under bump metal structure having the first diameter, wherein the fourth under bump metal structure and the first under bump metal structure are in an outermost column of the plurality of under bump metal structures and are immediately adjacent to each other; a fifth under bump metal structure having the first diameter, wherein the fourth under bump metal structure and the fifth under bump metal structure are in an outermost row of the plurality of under bump metal structures and are immediately adjacent to each other, and wherein a distance between the fourth under bump metal structure and the fifth under bump metal structure is greater than a distance between the second under bump metal structure and the third under bump metal structure; a first bump formed over the first under bump metal structure; and a second bump formed over the second under bump metal structure, wherein a top surface of the first bump is level with a top surface of the second bump, and wherein a first sidewall of an edge portion of the second under bump metal structure is covered by the second bump and a second sidewall of the edge portion of the second under bump metal structure is not covered by the second bump.