Winding-Type Coil Component Asymmetric Wire Disposition
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Solution Overview
Problem
In winding-type coil components, such as common mode choke coils, the stray capacitance between wires and a mount board is not balanced, leading to differences in capacitance that deteriorate mode conversion characteristics.
Innovation Solution
A winding-type coil component design with a core having flange portions and wires wound around it, where the wires are twisted and their positions shifted in the circumferential direction to equalize the length of wire portions closer to the mount board, reducing the difference in stray capacitance between the wires.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If two wires are twisted together to form a twisted wire, then the form of the first wire and the second wire can be made substantially the same, but the stray capacitance occurring in association with the first wire and the stray capacitance occurring in association with the second wire are not balanced
Solution Approach 1:
The patent applies asymmetry by intentionally creating different dispositions of the first and second wires in the twisted wire portion. Specifically, in some turns, the first wire is disposed closer to the mount board than the second wire, while in other turns, the second wire is disposed closer to the mount board than the first wire. This asymmetric arrangement balances the stray capacitance between the wires and the mount board, improving mode conversion characteristics.
2Productivity
If the first and second wires are wound around the winding core portion while twisting automatically by equipment in mass production, then all of the turns in the twisted wire have the same disposition of the first wire and second wire, but the difference between the stray capacitance occurring between the first wire and the mount board and the stray capacitance occurring between the second wire and the mount board accumulates and becomes larger
Solution Approach 1:
The patent applies periodic action by creating a periodic pattern in the disposition of wires through multiple twisting operations. The twisting operation is performed multiple times (e.g., 2 or more twists) in a periodic manner, causing the wires to alternately change positions relative to the mount board. This periodic twisting ensures that both wires experience similar stray capacitance conditions on average, preventing capacitance imbalance while maintaining mass production efficiency.
3Ease of manufacture
If the twisting operation and the winding operation are in synchronism, then the twisted wire includes some turns which have the same disposition of the first wire and the second wire, but either one of the stray capacitance occurring between the first wire and the mount board and the stray capacitance occurring between the second wire and the mount board is larger in each turn
Solution Approach 1:
The patent applies dynamics by making the disposition of wires dynamic rather than static. Through multiple twisting operations, the wires dynamically change their relative positions and distances to the mount board across different turns. This dynamic arrangement ensures that no single wire consistently maintains a larger stray capacitance, as the positions are continuously exchanged through the periodic twisting action.
Data Source
AI summary
A winding-type coil component includes a first wire and a second wire having a twisted wire portion where the first wire and the second wire are twisted together. Switching positions of the first wire and the second wire in the twisted wire portion are shifted in a circumferential direction of a winding core portion every turn.