Switching Module Common-Mode Suppression Structure for Fast Switching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing switching devices and modules generate common mode noise due to high-speed switching control, which affects nearby electronic devices and communication systems, and existing noise suppression techniques are inadequate.
Innovation Solution
A switching device and module with a common mode current suppression structure that includes insulating layers and conductive layers to maintain a constant potential, preventing the flow of common mode current and reducing noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If high-speed switching control is performed to improve device efficiency, then switching speed is improved, but common mode noise is generated
Solution Approach 1:
A common mode potential equalizing circuit is introduced as an intermediary component between the switching element and ground. This circuit includes a capacitor connected between the switching element and ground, and a resistor connected in parallel with the capacitor. The intermediary circuit provides a controlled path for common mode current, equalizing the potential and suppressing noise generation while allowing high-speed switching to continue
Solution Approach 2:
The impedance characteristics of the common mode potential equalizing circuit are adjusted by selecting appropriate capacitor and resistor values. The capacitor provides low impedance at high frequencies to shunt common mode noise, while the resistor provides damping. By changing these parameters, the circuit effectively suppresses common mode noise across different switching frequencies and conditions
2Object-generated harmful factors
If existing noise suppression techniques are used, then some noise reduction is achieved, but common mode noise still flows and suppression is inadequate
Solution Approach 1:
The common mode potential equalizing circuit acts as an intermediary that specifically targets the common mode current path. Unlike simple shielding or filtering approaches, this circuit directly addresses the potential difference that drives common mode noise by providing a controlled equalization path through the capacitor-resistor combination
Solution Approach 2:
The circuit maintains equipotential conditions between different parts of the circuit by providing a low-impedance path to ground through the capacitor. This equalizes the potential across the switching element and surrounding structures, preventing potential differences that would otherwise drive common mode noise currents
3Object-generated harmful factors
If insulation between semiconductor chip and heat dissipation conductor is implemented, then common mode current path is blocked, but thermal dissipation may be affected
Solution Approach 1:
The insulation structure is segmented into multiple discrete insulating layers rather than a single thick layer. This segmentation allows for optimized thermal management at each interface while maintaining electrical isolation. The multiple layers provide cumulative insulation effect while distributing thermal resistance across several thin interfaces
Solution Approach 2:
Different insulating materials with complementary properties are used in combination. Materials are selected to provide both electrical insulation and acceptable thermal conductivity. The composite structure balances electrical isolation requirements with thermal dissipation needs, using materials that offer different strengths in these two properties
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 suppression structure effectively prevents common mode current flow, reducing noise and allowing for faster switching control, thereby improving device performance.
Implementation Method 1
a first insulating layer joined on the heat dissipation conductor; an electric conductive layer joined on the first insulating layer
Implementation Method 2
a heat dissipation conductor arranged below the semiconductor chip
Data Source
AI summary
Provided is a switching device 1 including a drain fin 103 arranged below a semiconductor chip 101 via a common mode current suppression structure 2. The common mode current suppression structure 2 includes a first insulating layer 2a joined on the drain fin 103, an electric conductive layer 2b joined on the first insulating layer 12a, a second insulating layer 2c joined on the electric conductive layer 2b, and an electrode conductor 2d joined on an upper surface of the second insulating layer 2c and joined to a drain electrode 101a of the semiconductor chip 101. The electric conductive layer 2b is electrically connected to a source electrode 101b of the semiconductor chip 101.