Die fracture detection and humidity protection with double guard ring arrangement
AssigneeFreescale Semiconductor, Inc.
InventorsJason R. Fender, Ngai Ming Lau
Life of this patent
Estimating the term…
Abstract
An electronic apparatus includes a semiconductor substrate, outer and inner guard rings disposed along a periphery of the semiconductor substrate, and first and second contact pads electrically coupled to the outer and inner guard rings, respectively. The outer and inner guard rings are electrically coupled to one another to define a conduction path between the first and second contact pads. Each of the outer and inner guard rings includes an Ohmic metal layer having a plurality of gaps and further includes conductive bridges across the gaps. The gaps of the outer guard ring are laterally offset from the gaps of the inner guard ring such that the Ohmic metal layers of the outer and inner guard rings laterally overlap.
Claims20
An electronic apparatus comprising:
- a semiconductor substrate;
- outer and inner guard rings disposed along a periphery of the semiconductor substrate;
- first and second contact pads electrically coupled to the outer and inner guard rings, respectively;
- wherein the outer and inner guard rings are electrically coupled to one another to define a conduction path between the first and second contact pads;
- wherein each of the outer and inner guard rings comprises an Ohmic metal layer having a plurality of gaps and further comprises conductive bridges across the gaps;
- wherein the gaps of the outer guard ring are laterally offset from the gaps of the inner guard ring such that the Ohmic metal layers of the outer and inner guard rings laterally overlap.
A method of fabricating an electronic apparatus, the method comprising:
- forming an Ohmic metal layer of outer and inner guard rings on a semiconductor substrate, the outer and inner guard rings being disposed along a periphery of the semiconductor substrate and patterned such that the Ohmic metal layer has a plurality of gaps;
- depositing an interconnect metal layer to form conductive bridges of the outer and inner guard rings, each conductive bridge spanning a respective gap of the plurality of gaps;
- wherein the outer and inner guard rings are electrically coupled to one another to define a conduction path between contact pads of the electronic apparatus;
- wherein the gaps of the outer guard ring are laterally offset from the gaps of the inner guard ring such that the Ohmic metal layers of the outer and inner guard rings laterally overlap.
A method of testing an electronic apparatus, the method comprising:
- connecting the electronic apparatus to a test system to direct current through a conduction path comprising outer and inner guard rings disposed along a periphery of a semiconductor substrate of the electronic apparatus, each guard ring comprising an Ohmic metal layer having a plurality of gaps laterally offset from the gaps in the other guard ring;
- measuring current through the conduction path;
- and
- comparing the measured current with a predetermined current level indicative of a configuration of the conduction path for authentication of the electronic apparatus.
Dependencies are inferred from the claim text.