Dual-Layer Power Inductor With Via-Connected Coils
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Solution Overview
Problem
Existing power inductors used in portable devices are not adequately compact, thin, or multifunctionalized to meet the demands of high-performance, reduced-size central processing units, and they struggle to achieve a good level of saturation current efficiently.
Innovation Solution
The inductor design includes a support member with a through-hole and a via hole, featuring a first and second coil with conductive layers, where the coils are connected by a via that covers the end surface of the first coil and the upper surface of the second coil, with a thin insulating support member and an encapsulant filling the through-hole, allowing for reduced thickness and increased magnetic permeability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If the support member thickness is reduced to make the inductor thinner, then the overall thickness is reduced, but the saturation current level deteriorates
Solution Approach 1:
The patent implements a nested structure where the first coil and second coil are positioned on opposite surfaces of the support member, with the via hole penetrating through the support member to connect them. This nested arrangement allows the magnetic fields of the two coils to interact constructively, enhancing the saturation current despite the reduced support member thickness of 10-20 μm.
Solution Approach 2:
The patent transitions from a single-layer coil structure to a three-dimensional dual-layer coil structure by positioning coils on both surfaces of the thin support member and connecting them through a via hole. This dimensional change enables the inductor to achieve high saturation current in a thinner profile by utilizing the vertical dimension for magnetic field enhancement.
2Reliability
If a via hole is added to connect the first and second coils, then the magnetic permeability is improved, but the device complexity increases
Solution Approach 1:
The via hole structure serves multiple functions simultaneously: it electrically connects the first and second coils, provides a pathway for magnetic field interaction to enhance permeability, and acts as a structural support element. This multi-functionality reduces the need for additional components, thereby limiting the increase in device complexity despite the added via hole feature.
3Volume of moving object
If the support member is made thinner, then the inductor becomes more compact, but the manufacturing precision requirements increase
Solution Approach 1:
The patent specifies a precise thickness range of 10-20 μm for the support member, optimizing this parameter to achieve the right balance between compactness and manufacturability. This parameter control, combined with the via hole depth and coil positioning, enables thin-profile construction while maintaining manufacturing feasibility through controlled parameter specifications.
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 design enhances the saturation current of the inductor while reducing the thickness of the support member and process costs, achieving a more compact and high-performance power inductor suitable for modern portable devices.
Implementation Method 1
achieving a good level of saturation current (Isat) through a simple process
Data Source
AI summary
An inductor includes a body including a support member, a coil, and an encapsulant encapsulating the support member and the coil and external electrodes disposed on an external surface of the body and connected to the coil, wherein the support member includes a through-hole and a via hole spaced apart from the through-hole, the coil includes a first coil disposed on one surface of the support member and a second coil disposed on the other surface of the support member opposing the one surface, the first and second coils are connected to each other by a via filling the via hole, and the via continuously covers an end surface of the first coil and an upper surface of the second coil.