Embedded Coil Assembly Using Wire Cage and Ferrite Ring
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Solution Overview
Problem
Conventional methods for embedding small toroidal coil assemblies in printed circuit boards and molded components are time-consuming and expensive due to the labor-intensive process of drilling and plating numerous tiny vias or hand wrapping metal windings around toroidal ferrite cores.
Innovation Solution
The use of semiconductor manufacturing techniques in a new manufacturing environment involving organic printed circuit boards and standalone inductor components encased in mold compound, where a ferrite ring is positioned within an annular void in a metal layer, and bond wires are connected to form a 'wire cage' around the ferrite ring, which is then embedded in a layer of mold compound, allowing for efficient patterning and etching to create multiple windings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional methods of drilling and plating tiny vias or hand wrapping metal windings are used, then coil assemblies can be embedded in printed circuit boards, but the production process becomes time-consuming and expensive
Solution Approach 1:
The patent replaces the mechanical process of hand-wrapping windings and drilling vias with a semiconductor manufacturing-style process. Conductive traces are deposited and patterned on a substrate to form coil windings, eliminating the need for manual wire wrapping and via drilling. This substitution of mechanical operations with deposition and patterning processes directly addresses the contradiction by improving ease of manufacture while increasing production speed.
2Reliability
If conventional methods of drilling and plating numerous tiny vias are used, then electrical connections can be established, but the manufacturing process becomes expensive and time-consuming
Solution Approach 1:
The patent extracts the need for via drilling and plating entirely from the manufacturing process. Instead of creating holes through the substrate to establish electrical connections, conductive traces are deposited directly on the substrate surface to form the coil windings and electrical connections. This extraction of the via-creation step eliminates the time-consuming and costly drilling and plating operations while maintaining reliable electrical connections through the deposited conductive traces.
3Ease of manufacture
If hand wrapping metal windings around toroidal ferrite cores is used, then coil assemblies can be formed, but the process becomes labor-intensive and expensive
Solution Approach 1:
The patent replaces the mechanical hand-wrapping process with automated deposition and patterning operations. Conductive material is deposited on the substrate and then patterned to form the coil windings around the ferrite core, eliminating manual labor. This substitution reduces both the labor intensity and manufacturing cost while simplifying the overall manufacturing process by using standard semiconductor-style fabrication techniques.
4Adaptability or versatility
If conventional embedding methods are used, then coil assemblies can be integrated into printed circuit boards, but production costs increase and efficiency decreases
Solution Approach 1:
The patent merges the coil winding formation process with the substrate fabrication process. The conductive traces are deposited and patterned on the same substrate that will serve as the printed circuit board, integrating the coil assembly creation with the board manufacturing. This merging of processes eliminates separate embedding steps, improves production efficiency, and maintains the adaptability of integrating coils into printed circuit boards.
Data Source
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AI summary
In described examples, a coil assembly includes a laterally disposed ferrite ring (150) having a central opening (152). A laterally disposed annular conductive member (186) is positioned above the ferrite ring (150) and has spaced-apart circumferential segments. Bond wires (154) are connected at opposite ends thereof to outer and inner portions of the spaced-apart circumferential segments. A layer of mold compound covers the ferrite ring (150) and the bond wires (154).