Embedded Inductor Module Structure for High-Q Power Packaging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Integrating inductors into integrated circuits (ICs) is challenging due to their large size, limited current handling, and insufficient quality factor (Q), leading to performance issues, and package-level integration with discrete inductors is expensive and complex.
Innovation Solution
A multi-layer substrate with a cavity and an embedded inductor module, where the inductor module includes conductive windings and a central core within a dielectric substrate, encapsulated in a mold compound, to enhance inductance and reduce resistance, thereby improving the quality factor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an on-wafer integrated inductor is used, then the inductor can be integrated into the IC, but the current handling ability is limited due to relatively high resistance
Solution Approach 1:
The patent transitions from planar on-wafer inductors to three-dimensional embedded inductors that extend vertically through multiple substrate layers. This dimensional change allows for longer conductor paths and larger effective areas without increasing the planar footprint, thereby reducing resistance and improving current handling capability while maintaining integration within the IC package.
Solution Approach 2:
The inductor structure is embedded within the multi-layer substrate, nesting the conductor and magnetic core within the substrate layers rather than placing them on the surface. This nested configuration allows the inductor to utilize the substrate structure itself, reducing parasitic effects and improving electrical performance.
2Reliability
If existing on-chip inductors are used, then integration is achieved, but the quality factor (Q) is insufficient which reduces circuit performance
Solution Approach 1:
The patent employs composite structures combining conductive materials, magnetic core materials, and dielectric substrate materials in a multi-layer configuration. This composite approach enables optimization of the quality factor by selecting materials with complementary properties, while the modular multi-layer structure manages complexity through standardized fabrication processes.
Solution Approach 2:
By extending the inductor structure into the vertical dimension with multiple substrate layers, the patent increases the effective inductance and quality factor without requiring larger planar areas. This three-dimensional approach improves performance while maintaining compact integration within the IC package.
3Reliability
If package level integration with discrete inductor or magnetic core block is used, then performance can be improved, but the cost increases and assembly process becomes complex
Solution Approach 1:
The patent merges the inductor structure with the substrate structure by embedding the conductor and magnetic core within the multi-layer substrate during fabrication. This integration eliminates the need for separate discrete inductor components and complex post-fabrication assembly steps, reducing both cost and manufacturing complexity while maintaining improved inductor performance.
Solution Approach 2:
The inductor structure is prepared and embedded within the substrate during the substrate fabrication process itself, before final IC assembly. This preliminary integration approach simplifies subsequent manufacturing steps and reduces assembly complexity compared to adding discrete inductors at the package level.
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 solution enables increased inductance and lower resistance, resulting in improved performance for power applications such as power converters, surpassing many existing inductor solutions.
Implementation Method 1
A central core of a magnetic mold compound is within at least a portion of the central region
Implementation Method 2
The inductor module includes a conductor embedded within a dielectric substrate between spaced apart first and second inductor terminals
Data Source
AI summary
An example method includes forming a cavity in a multi-layer substrate of a leadframe. The cavity extends from a first substrate surface of the leadframe into the multi-layer substrate to define a cavity floor spaced from the first substrate surface by a cavity sidewall, and at least one conductive terminal is on the cavity floor. The method also includes placing an inductor module in the cavity, in which the inductor module includes a conductor embedded within a dielectric substrate between spaced apart first and second inductor terminals of the inductor module. The method also includes coupling at least one of the first and second inductor terminals to the at least one conductive terminal on the cavity floor. The method also includes encapsulating the inductor module and at least a portion of the leadframe with a mold compound.