3D Interlaced Inductor Structure for Conductor Loss Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Inductors in integrated circuits face challenges with conductor loss and reduced quality due to metal thickness limitations and substrate interference, which degrade their Q-factor performance.
Innovation Solution
The inductor structure features a symmetrically disposed spiral coil configuration with interlaced connection leads of varying heights and a gain pattern positioned under specific interlaced zones to increase the cross-sectional area of conductors, reducing conductor loss and enhancing Q-factor performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the metal thickness of inductor is increased to reduce conductor loss, then the Q-factor is improved, but the device complexity and manufacturing difficulty increase due to IC process limitations
Solution Approach 1:
The patent transitions from planar 2D inductor structures to 3D vertically stacked spiral coil structures. Multiple spiral coils are stacked at different heights above the substrate, utilizing the vertical dimension to increase the effective conductor cross-sectional area without increasing planar footprint. This dimensional transition allows achieving lower conductor loss while maintaining IC process compatibility and reasonable structural complexity.
Solution Approach 2:
The patent implements nested stacking where multiple spiral coils are vertically arranged and interconnected through vias. The coils are nested in the vertical direction with each coil positioned at a different height, forming a compact 3D structure. This nesting approach maximizes the use of vertical space to increase effective conductor area without proportionally increasing device footprint or manufacturing complexity.
2Loss of energy
If the wire width of inductor coil is increased to reduce conductor loss, then the Q-factor is improved, but the coupling between coils and substrate increases degrading inductor efficiency
Solution Approach 1:
The patent uses vertical stacking to increase effective conductor width in the vertical dimension rather than increasing planar wire width. By stacking multiple spiral coils at different heights and connecting them through vias, the effective cross-sectional area for current flow is increased without expanding the planar footprint. This prevents increased capacitive coupling with the substrate while achieving lower conductor loss.
Solution Approach 2:
The patent divides the inductor into multiple separate spiral coil segments stacked vertically. Each spiral coil is an independent conducting element positioned at a different height. This segmentation allows the current to be distributed across multiple separated conductors rather than requiring a single wide conductor, thereby reducing substrate coupling while maintaining low conductor loss through the combined effect of multiple paths.
3Loss of energy
If symmetric differential inductor structure is used to improve performance, then the Q-factor is improved, but the manufacturing precision requirements increase due to symmetry constraints
Solution Approach 1:
The patent employs asymmetric grounding techniques where the even-mode and odd-mode spiral coils are grounded at different positions and through different numbers of vias. This asymmetric grounding configuration intentionally breaks the perfect symmetry to compensate for process variations and substrate effects. By strategically placing ground vias at different locations and with different densities, the design achieves better overall performance and reduced sensitivity to manufacturing tolerances while maintaining the beneficial effects of the differential structure.
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 configuration effectively improves the Q-factor of inductors by reducing conductor loss and achieving more symmetric responses in symmetric differential inductors, maintaining efficiency across the required frequency range for RF circuits.
Implementation Method 1
as an inductor acquires energy storing and releasing functions through electromagnetic conversion
Implementation Method 2
The gain pattern is disposed under the first connection lead at the (2N−1)th interlaced zone counted from the most-outer turn up and electrically connected to the corresponding first connection lead
Data Source
AI summary
An inductor structure disposed over a substrate includes a first spiral coil, a second spiral coil and at least a gain pattern. The first spiral coil includes first conducting wires and first connection leads, wherein each first connection lead connects two adjacent first conducting wires. The second spiral coil includes second conducting wires and second connection leads, wherein each second connection lead connects two adjacent second conducting wires. The second spiral coil and the first spiral coil are symmetrically disposed about a plane of symmetry and in series connection to form a spiral coil structure with 2N turns, wherein N is a positive integral, and are spaced from the substrate by different heights to form 2N−1 interlaced zones. The gain pattern is disposed under the first connection lead at the (2N−1)th interlaced zone counted from the most-outer turn up and electrically connected to the corresponding first connection lead.