Redistribution Layer Conductive Line Removal in Scribe-Line Area
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Solution Overview
Problem
The existing methods for singulating integrated circuit structures through the scribe-line area often propagate cracks due to sawing through test pads, rendering the die inoperable, as the redistribution layer (RDL) conductive material remains atop the conductive test pads, leading to crack generation during dicing.
Innovation Solution
The method involves forming a conductive line of the redistribution layer within the scribe-line area by creating openings in the radiation-imageable material and insulating material, allowing the RDL-conductive material to be patterned and removed from the scribe-line area, thereby reducing the risk of crack generation during dicing by separating the RDL-conductive lines between individual dies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If RDL-conductive material is present in the scribe-line area during dicing, then electrical connectivity is maintained, but crack propagation into die area occurs rendering the die inoperable
Solution Approach 1:
The patent extracts the RDL-conductive material from the scribe-line area by forming openings through the insulating material and selectively removing conductive material in the scribe-line region while maintaining it in the die area. This extraction eliminates the harmful effect of crack propagation through test pads during dicing, while preserving electrical connectivity where needed.
Solution Approach 2:
The patent segments the conductive material distribution by creating distinct regions: conductive material is retained in die areas for electrical connectivity but removed from scribe-line areas to prevent cracking. This segmentation is achieved through selective patterning processes that treat different regions of the substrate differently.
2Object-affected harmful factors
If RDL-conductive material is removed from scribe-line area, then crack propagation is reduced, but electrical connectivity in scribe-line area is lost
Solution Approach 1:
The patent applies local quality by giving different regions different properties: the die area retains conductive material for electrical connectivity, while the scribe-line area has conductive material removed to prevent cracking. This spatial differentiation of material properties resolves the contradiction between maintaining connectivity and preventing damage.
3Ease of operation
If test pads are exposed in scribe-line area for testing, then test access is enabled, but sawing through test pads causes cracks
Solution Approach 1:
The patent performs preliminary action by removing RDL-conductive material from the scribe-line area before the dicing process. This advance removal prevents cracks from propagating through the test pads during sawing, while the test pads remain accessible for electrical testing through the exposed pad structures.
Data Source
AI summary
A substrate comprises a pair of immediately-adjacent integrated-circuit dies having scribe-line area there-between. At least one of the dies comprises insulting material above integrated circuitry. The insulating material has an opening therein that extends elevationally inward to an upper conductive node of integrated circuitry within the one die. The one die comprises a conductive line of an RDL above the insulating material. The RDL-conductive line extends elevationally inward into the opening and is directly electrically coupled to the upper conductive node. The insulating material has a minimum elevational thickness from an uppermost surface of the upper conductive node to an uppermost surface of the insulating material that is immediately-adjacent the insulating-material opening. Insulator material is above a conductive test pad in the scribe-line area. The insulator material has an opening therein that extends elevationally inward to an uppermost surface of the conductive test pad. The insulator material has a minimum elevational thickness from the conductive-test-pad uppermost surface to an uppermost surface of the insulator material that is immediately-adjacent the insulator-material opening and that is less than said minimum elevational thickness of the insulating material. Methods are disclosed.