Power Converter Noise Reduction via Insulated Insertion Member
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing power converter designs face issues with noise generation due to parasitic capacitance between semiconductor switches and heatsinks, leading to increased thermal resistance, high costs, and spatial restrictions, as well as inadequate vibration resistance and durability.
Innovation Solution
A power converter design featuring an insertion member with a conductive member and insulator between the switching element and radiator, connected by a flexible line, which encloses noise currents and reduces vibration influences, while maintaining effective heat transfer and cost efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a heatsink is connected to frame ground to cool the semiconductor switch, then heat dissipation is improved, but parasitic capacitance is generated between the switch and heatsink causing noise
Solution Approach 1:
An insertion member is introduced as an intermediary component between the semiconductor switch and heatsink. This insertion member includes a conductive member with insulating layers that provide electrical isolation, preventing parasitic capacitance formation while allowing thermal conduction to maintain effective heat dissipation.
2Object-generated harmful factors
If a low-permittivity insulation material is provided between the switch and heatsink to reduce parasitic capacitance, then noise is reduced, but thermal resistance increases reducing cooling efficiency
Solution Approach 1:
The insertion member employs a composite structure combining conductive materials (for thermal conduction) with insulating materials (for electrical isolation). This composite approach enables simultaneous achievement of low thermal resistance and low parasitic capacitance, resolving the contradiction between cooling efficiency and noise reduction.
3Stability of the object's composition
If the heatsink is fixed rigidly to reduce vibration, then structural stability is improved, but vibration resistance and durability are reduced
Solution Approach 1:
The connecting line between the heatsink and circuit board is designed with flexibility, allowing it to absorb vibrations and mechanical stresses. This flexible connection maintains structural stability while improving vibration resistance and durability by preventing stress concentration and fatigue failure.
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
The solution effectively reduces noise output, enhances durability, and allows for flexible arrangement of components by enclosing noise currents and absorbing vibrations, while maintaining efficient heat transfer and reducing production costs.
Implementation Method 1
a parasitic capacitance is generated between the semiconductor switch and the heatsink
Implementation Method 2
the connecting line which is flexible and electrically connects the conductive member and the line to each other
Implementation Method 3
The heatsink HS has a function of cooling by externally radiating heat generated on the semiconductor switch SW
Implementation Method 4
The heatsink HS has a function of cooling by externally radiating heat generated on the semiconductor switch SW
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Provided is a power converter which is applied to a power converter equipped with a switching element provided on a line, and a radiator connected to a predetermined potential such as a ground potential. The power converter reduces noise which is caused by a parasitic capacitance generated between the switching element and the radiator and which is output to an input side of the power converter, and the power converter has durability against vibration. A noise eliminator 11 in which a conductive member is covered with insulator is provided between the switching element (semiconductor switch SW) and the radiator (heatsink HS). A flexible connecting line 11c connected to a conductive member 11a of the noise eliminator 11 is connected to an on-board line B1 disposed on a circuit board B.