Magnetically Decoupled Inductor Structures in IC Dies
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The formation of multiple inductor structures in an integrated circuit die can lead to degradation of electrical characteristics such as inductance and quality factor due to magnetic coupling between inductor structures, which is exacerbated when high frequency signals are involved, and increasing the distance between them is not always practical due to limited space.
Innovation Solution
The implementation of magnetically decoupled inductor structures, where conductive traces and guard rings are used to separate and reduce magnetic coupling between inductor structures by providing distinct ground pathways and connecting them through conductive traces, thereby reducing magnetic interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple inductor structures are formed in an integrated circuit die, then the functionality and integration density are improved, but magnetic coupling between inductor structures degrades electrical characteristics such as inductance and quality factor
Solution Approach 1:
The patent divides the ground connection system into separate ground pathways for each inductor structure. Each inductor has its own dedicated ground path that is magnetically isolated from other inductors, preventing magnetic coupling while maintaining high integration density. This segmentation of the ground system resolves the contradiction by allowing multiple inductors to coexist without mutual interference.
Solution Approach 2:
The patent introduces conductive guard rings as intermediary structures between adjacent inductor structures. These guard rings act as magnetic shields that redirect magnetic flux and prevent coupling between inductors. The guard rings serve as a mediator that enables close spacing of inductors while maintaining electrical characteristic integrity.
2Reliability
If the distance between inductor structures is increased, then magnetic coupling is reduced and electrical characteristics are improved, but the available space on the integrated circuit die is consumed
Solution Approach 1:
The patent moves the ground connection paths to different physical layers within the integrated circuit structure. By utilizing vertical stacking and multi-layer construction, the ground pathways can be routed in three-dimensional space rather than requiring increased horizontal spacing. This allows inductors to be placed close together in the planar view while maintaining magnetic isolation through separated ground paths in adjacent layers.
Solution Approach 2:
The patent implements nested structures where conductive guard rings are positioned between and around inductor structures in a compact arrangement. The guard rings are nested within the available space between inductors, effectively using the inter-inductor region for magnetic shielding purposes. This nesting approach maximizes space utilization while providing magnetic isolation.
3Object-affected harmful factors
If separate ground pathways are provided for each inductor structure, then magnetic coupling is reduced, but the device complexity increases
Solution Approach 1:
The conductive guard rings serve multiple functions simultaneously: they act as magnetic shields between inductors, provide additional ground pathways, and serve as structural elements that define the inductor boundaries. This multi-functionality reduces the need for separate dedicated shielding structures, thereby limiting the increase in device complexity while still achieving magnetic decoupling.
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
This approach effectively reduces magnetic coupling between inductor structures, maintaining or improving their electrical characteristics even at high frequencies without the need for increased physical spacing, thus enhancing the performance of integrated circuit die components.
Implementation Method 1
magnetic couplings generated by one inductor structure on another inductor structure negatively affect the electrical characteristics
Implementation Method 2
The conductive trace that couples the first and second ground conductors may magnetically decouple the first and second inductor structures
Implementation Method 3
The conductive guard ring structures may also magnetically decouple the first and second inductor structures
Data Source
AI summary
In one embodiment, an integrated circuit die includes first and second inductor structures, a first ground conductor, a second ground conductor and a conductive trace. The first ground conductor provides a first ground pathway for the first inductor structure. The second ground conductor provides a second ground pathway for the second inductor structure. The conductive trace coupled between the first and second ground conductors may magnetically decouple the first and second inductor structures. In addition, the integrated circuit die may also include conductive guard ring structures that surround the first and second inductor structures. One of the conductive guard ring structures may be connected to the first grounding pathway and the other conductive guard ring structure may be connected to the second grounding pathway. The conductive guard ring structures may further magnetically decouple the first and second inductor structures.