Chamfered corner crackstop for an integrated circuit chip

摘要

A corner crackstop is formed in each of the four corners of an integrated circuit (IC) chip, in which the corner crackstop differs structurally from a portion of the crackstop disposed along the sides of the IC chip. Each corner crackstop includes a plurality of layers, formed on a top surface of a silicon layer of the IC chip, within a perimeter boundary region that comprises a triangular area, in which a right angle is disposed on a bisector of the corner, equilateral sides of the triangle are parallel to sides of the IC chip, and the right angle is proximate to the corner relative to a hypotenuse of the triangle. The plurality of layers of the corner crackstop include crackstop elements, each comprising a metal cap centered over a via bar, in which the plurality of layers of the corner crackstop is chamfered to deflect crack ingress forces by each corner crackstop.

主权项

1. A corner crackstop comprising:
a plurality of n metallization layers formed on a silicon layer of an integrated circuit (IC) chip above a perimeter boundary region of a corner of said IC chip, said perimeter boundary region comprising a triangle, a right angle of said triangle being disposed proximately to said corner and sides of said triangle being parallel to sides of said IC chip; and a number of crackstop elements disposed within each of said n metallization layers, each of said crackstop elements being longitudinally oriented in parallel to a hypotenuse of said triangle and being limited in length by said sides of said triangle,
a first crackstop element of a first metallization layer disposed most proximately to said right angle and having a smallest length, a second crackstop element of said first metallization layer adjoined distally to said first crackstop element and having a greater length, and an nth crackstop element of said first metallization layer adjoined distally to an (n−1)th crackstop element and having a greatest length,a first crackstop element of a second metallization layer aligned vertically over said second crackstop element of said first metallization layer and having said greater length, and an (n−1)th crackstop element of said second metallization layer aligned vertically over said nth crackstop element of said first metallization layer and having said greatest length, anda single crackstop element of an nth metallization layer aligned vertically over a second crackstop element of an (n−1)th metallization layer and having said greatest length.