Self-Healing Crack Stop Structure for IC Reliability
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Solution Overview
Problem
Conventional crack stop structures, such as guard rings, can be damaged during the dicing process and occupy valuable real estate on integrated circuit chips, while failing to prevent crack propagation effectively.
Innovation Solution
A self-healing crack stop structure formed in dielectric layers around the active region of an integrated circuit chip, utilizing encapsulated self-healing materials within a resin matrix that can seal cracks and prevent further propagation, including microcapsules filled with monomers like dicyclopentadiene and Grubbs' catalyst to expedite healing at room temperature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional guard rings are used as crack stop structures, then crack propagation can be prevented, but valuable silicon real estate is occupied and the structures can be damaged during dicing
Solution Approach 1:
The patent changes the material parameters of the crack stop structure by using self-healing materials with different mechanical properties (elastic modulus, strength) than conventional guard rings. This allows the structure to heal cracks dynamically while occupying less area, as the self-healing mechanism compensates for the reduced structural mass.
Solution Approach 2:
The patent employs composite materials consisting of self-healing polymers combined with reinforcing agents or fillers. This composite approach provides both the crack-stop function and the self-healing capability, reducing the need for large structural footprints while maintaining reliability.
2Reliability
If conventional guard rings are used as crack stop structures, then crack propagation can be prevented, but the structures can be damaged due to dicing issues
Solution Approach 1:
The patent implements self-service by enabling the crack stop structure to automatically repair itself after damage. The self-healing mechanism activates when cracks form during dicing or operation, restoring the structure's integrity without external intervention and preventing permanent damage.
Solution Approach 2:
The patent applies beforehand cushioning by incorporating self-healing materials that can absorb and mitigate the impact of dicing stresses. The material's viscoelastic properties and self-healing capability provide a buffer against mechanical damage during the dicing process.
3Area of stationary object
If self-healing material is used in crack stop structure, then crack propagation can be prevented and silicon real estate is freed, but the material must effectively seal cracks under stress
Solution Approach 1:
The patent applies local quality by concentrating self-healing materials specifically at crack-prone locations or interfaces within the crack stop structure. This localized application ensures effective crack sealing where needed most while minimizing overall material usage and preserving silicon real estate.
Solution Approach 2:
The patent uses composite materials that combine self-healing polymers with structurally robust components. This composite approach maintains crack sealing effectiveness under stress while reducing the overall footprint of the crack stop structure, thereby freeing silicon real estate.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The self-healing crack stop structure effectively prevents crack propagation and delamination, protecting the active area from mechanical and moisture damage, while freeing up silicon real estate by automatically repairing cracks and maintaining chip integrity.
Implementation Method 1
The crack stop comprises self healing material which, upon propagation of a crack, is structured to seal the crack and prevent further propagation of the crack.
Implementation Method 2
The crack stop structure includes encapsulated self healing material within a resin matrix having a catalyst.
Implementation Method 3
The crack stop structure includes encapsulated self healing material within a resin matrix having a catalyst.
Data Source
AI summary
A self-healing crack stop structure and methods of manufacture are disclosed herein. The structure comprises a crack stop structure formed in one or more dielectric layers and surrounding an active region of an integrated circuit chip. The crack stop comprises self healing material which, upon propagation of a crack, is structured to seal the crack and prevent further propagation of the crack.