3D Inductors for PMIC EMI Shielding and Size Reduction
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Solution Overview
Problem
The miniaturization of power supply packages is limited by the size and placement of off-chip inductors, which cause electromagnetic interference and restrict vertical and horizontal size reduction due to their larger size and separate connection distances from the power supply die.
Innovation Solution
Integration of 3-dimensional (3D) inductors around a power management integrated circuit (PMIC) die, with electrical coupling to both a lower and upper redistribution layer, allowing for closer proximity and easier customization, and the use of integrated electromagnetic interference (EMI) shields designed similarly to the 3D inductors for reduced size and improved performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If off-chip SMD inductors are used, then electromagnetic interference is mitigated, but the package size increases and quality factor decreases
Solution Approach 1:
The patent combines the inductor and EMI shield into a single integrated component structure. The inductor windings are formed around a magnetic core that also serves as the EMI shield, eliminating the need for separate EMI shielding components. This merging reduces the overall package volume while maintaining EMI mitigation capabilities through the inherent shielding properties of the magnetic core.
Solution Approach 2:
The patent implements a nested structure where the EMI shield is positioned inside or around the inductor windings. The magnetic core serves as an inner element that provides both inductance and EMI shielding, with additional shielding layers potentially nested within or around the external magnetic shielding structure. This nested arrangement maximizes space utilization and reduces package size.
2Object-affected harmful factors
If off-chip SMD inductors are used, then electromagnetic interference is mitigated, but the quality factor decreases due to interconnection distances
Solution Approach 1:
The patent merges the inductor and EMI shield into a single integrated component structure. The inductor windings are formed around a magnetic core that also serves as the EMI shield, eliminating the need for separate EMI shielding components. This merging reduces the overall package volume while maintaining EMI mitigation capabilities through the inherent shielding properties of the magnetic core.
Solution Approach 2:
The patent introduces a magnetic core as an intermediary element that serves dual functions: providing the magnetic path for inductance and acting as an EMI shield. This intermediary structure reduces interconnection distances by integrating the EMI shielding function directly at the inductor location, thereby improving quality factor while maintaining EMI protection.
3Volume of moving object
If 3D inductors are integrated around PMIC die, then package size is reduced, but manufacturing complexity increases
Solution Approach 1:
The patent transitions from planar 2D inductor layouts to three-dimensional inductor structures that wrap around the PMIC die. The inductor windings are formed in multiple layers and dimensions, utilizing vertical space to achieve higher inductance values in a smaller footprint. This dimensional change enables compact integration while maintaining manufacturability through established 3D IC packaging techniques.
Solution Approach 2:
The patent designs the 3D inductor structure to serve multiple functions: providing inductance for power conversion, acting as an EMI shield through its magnetic core, and serving as a mechanical support structure for routing connections. This multi-functionality reduces the need for separate components and simplifies the overall manufacturing process despite the three-dimensional complexity.
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 enables smaller, more efficient power supply packages with higher quality factor inductors and simplified EMI shielding, enhancing design and manufacturing efficiencies while allowing for tailored performance characteristics.
Implementation Method 1
A plurality of 3-dimensional (3D) inductors are disposed around the PMIC die and electrically coupled to the lower RDL and an upper RDL
Implementation Method 2
integrated electromagnetic interference (EMI) shields designed similarly to the 3D inductors
Data Source
AI summary
A power supply package is disclosed, including a power management integrated circuit (PMIC) die with a plurality of switching circuits, and a plurality of integrated 3-dimensional (3D) inductors disposed around the PMIC die. Each 3D inductor corresponds to a switching circuit and is electrically coupled to first and second connections for the corresponding switching circuit. An integrated electromagnetic interference (EMI) shield is disposed between the PMIC and the 3D inductors.