Plated Power Inductor Electrodes With Insulation Against Shorting
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Solution Overview
Problem
Power inductors face issues with external electrode short-circuiting with shield cans and have weak tensile strength due to weak coupling forces, leading to potential separation from electronic devices.
Innovation Solution
The power inductor design includes a body with metal powder and insulation material, featuring a coil pattern and external electrode formed through copper plating, with an internal insulation layer of parylene and a capping insulation layer to prevent exposure and enhance coupling strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the external electrode extends to the top surface of the power inductor, then the electrical connection is improved, but the external electrode may be short-circuited with the shield can
Solution Approach 1:
An insulation layer is introduced as an intermediary between the external electrode and the shield can. This insulation layer prevents direct contact and potential short-circuiting while allowing the external electrode to extend to the top surface for electrical connection purposes.
Solution Approach 2:
A thin film insulation layer is applied over the external electrode or at critical areas where the electrode extends to the top surface. This thin film provides electrical isolation from the shield can while maintaining the electrical connection functionality of the external electrode.
2Ease of manufacture
If the external electrode is formed by applying conductive paste, then the manufacturing process is simplified, but the external electrode may be separated from the body due to weak coupling force
Solution Approach 1:
The external electrode is formed using a composite structure combining conductive paste with metal powder or metallic particles. This composite approach maintains the ease of manufacturing through paste application while significantly improving the coupling force and tensile strength through the metallic reinforcement.
Solution Approach 2:
The body material itself is formulated as a composite of polymer matrix and metal powder, providing inherent tensile strength and coupling force. The external electrode formed with conductive paste benefits from this composite structure, preventing separation under tensile load.
3Reliability
If metal powder is used to manufacture the body, then the saturation magnetization value increases, but the eddy current loss and hysteresis loss increase at high frequency
Solution Approach 1:
The body is constructed with metal powder particles distributed within a polymer matrix, creating local regions of high magnetization where metal powder is concentrated, while the polymer matrix between particles provides insulation that suppresses eddy currents. This local quality differentiation allows simultaneous achievement of high saturation magnetization and low eddy current loss.
Solution Approach 2:
A composite material consisting of metal powder and polymer is used to manufacture the body. The metal powder provides high saturation magnetization while the polymer matrix insulates individual particles, preventing eddy current formation and reducing energy loss at high frequencies.
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 effectively prevents external electrode short-circuiting and improves tensile strength, ensuring the power inductor remains securely attached to electronic devices.
Implementation Method 1
at least a portion of the external electrode includes the same material as the coil pattern... formed through copper plating
Implementation Method 2
an internal insulation layer of parylene... to prevent exposure and enhance coupling strength
Data Source
Figure 1~2
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AI summary
Provided is a power inductor. The power inductor includes a body including metal powder and an insulation material, at least one base provided in the body, at least one coil pattern disposed on at least one surface of the base, and an external electrode disposed on each of at least two side surfaces of the body. At least a portion of the external electrode is made of the same material as the coil pattern.