Embedded Magnetic Component Air Gap Reduction
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Solution Overview
Problem
Existing embedded magnetic components face challenges in achieving high isolation performance due to limitations in dielectric strength, leading to increased device size and potential failures from air bubbles and contamination, especially when dealing with high voltages like 250 Vrms.
Innovation Solution
A method involving a magnetic core embedded in a cavity within an insulating substrate with discrete adhesive points for secure attachment, maintaining an air gap, and additional insulating layers to reduce isolation distance and enhance electrical insulation, allowing for smaller device designs while meeting safety standards.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If epoxy gel is used to fill the cavity to embed the magnetic component, then the magnetic component is fully covered and secured, but air bubbles form in the epoxy gel during solidification which can expand during reflow soldering and cause device failure
Solution Approach 1:
The patent removes the harmful epoxy gel filling from the cavity, extracting the source of air bubble formation. Instead of filling the cavity with epoxy gel, the magnetic component is embedded using adhesive applied to discrete locations, eliminating the bulk material that traps air bubbles during solidification.
Solution Approach 2:
The patent converts the potential harm of air bubbles by eliminating the epoxy gel filling that causes them. The adhesive application method used allows for controlled bonding without trapping air, transforming the problematic filling process into a beneficial secure mounting solution.
2Reliability
If the cavity is filled with epoxy gel to secure the magnetic component, then the component is fixed in place, but the isolation distance between primary and secondary windings must be large to achieve high isolation performance
Solution Approach 1:
The patent changes the dielectric parameter by replacing air (low dielectric strength) with an insulating layer material (high dielectric strength) in the cavity. This parameter change allows the isolation distance to be reduced while maintaining or improving isolation performance, as the insulating layer material provides better electrical insulation properties than air.
3Object-affected harmful factors
If the cavity is left empty or filled with air to avoid epoxy gel bubbles, then air gaps exist around the magnetic core, but the isolation performance is limited by the dielectric strength of air
Solution Approach 1:
The patent introduces an insulating layer material as an intermediary substance between the magnetic component and the surrounding environment. This intermediary provides both mechanical support and superior electrical insulation compared to air, eliminating contamination risks while maintaining high isolation performance through its higher dielectric strength.
4Reliability
If additional insulating layers are added to improve isolation performance, then electrical insulation is enhanced and isolation distance is reduced, but the device complexity increases
Solution Approach 1:
The patent merges multiple functions into the insulating layer: it provides electrical insulation, structural support for the magnetic component, and contamination protection. By combining these functions into a single integrated layer rather than separate components, the electrical insulation is enhanced without proportionally increasing device 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 significantly reduces the isolation distance between primary and secondary windings to 0.4 mm, enabling more compact designs and improved reliability by minimizing air gaps and contamination risks, while ensuring compliance with safety regulations like EN/UL60950.
Implementation Method 1
applying one or more spots of adhesive to discrete locations inside the cavity or on the magnetic core to form one or more adhesive coated attachment points for the magnetic core
Data Source
AI summary
In a method of manufacturing an embedded magnetic component, a cavity is formed in an insulating substrate. One or more drops of adhesive are applied to the cavity and a magnetic core is inserted in the cavity. The cavity and the magnetic core are then covered with a first insulating layer. Through holes are formed through the first insulating layer and the insulating substrate, and plated up to form conductive vias. Metallic traces are added to exterior surfaces of the first insulating layer and the insulating substrate to form upper and lower winding layers. The metallic traces and the conductive vias form the windings for an embedded magnetic component, such as a transformer or an inductor.