Semiconductor Device With Differential Copper Foil Thickness
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Solution Overview
Problem
Power semiconductor modules face inefficiencies due to unnecessarily thick copper foil on control electrodes, which is wasteful and difficult to form selectively, as they are produced with the same thickness as main electrodes, despite carrying smaller currents.
Innovation Solution
A semiconductor device design featuring a multi-layered substrate with separate conductive members for main and control electrodes, where the first conductive member is thicker than the second, allowing larger current flow to the main electrode while preventing wasteful thickness on the control electrode, and enabling selective formation of thinner conductive members for control electrodes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the copper foil thickness is increased to handle larger currents, then the current carrying capacity is improved, but the control electrode copper foil becomes unnecessarily thick and wasteful
Solution Approach 1:
The patent applies different copper foil thicknesses to different functional areas: the main electrode uses thick copper foil (0.1-0.5mm) for high current capacity, while the control electrode uses thin copper foil (0.03-0.05mm) for low current requirements. This local differentiation eliminates material waste while maintaining electrical performance.
Solution Approach 2:
The patent segments the conductive foil structure into separate main electrode foil and control electrode foil layers. The main electrode foil is positioned beneath the main electrode pad, while the control electrode foil is positioned beneath the control electrode pad, allowing independent thickness optimization for each segment based on its current requirements.
2Quantity of substance
If the copper foil thickness is increased, then the current carrying capacity is improved, but the selective formation of narrow copper foil portions becomes difficult
Solution Approach 1:
The patent implements local quality by specifying that the main electrode copper foil has thickness of 0.1-0.5mm while the control electrode copper foil has thickness of 0.03-0.05mm. This local differentiation allows each region to be optimized for its specific function without compromising manufacturing feasibility.
Solution Approach 2:
The patent employs preliminary action by forming the different thickness copper foil portions through a controlled etching process that selectively removes copper from specific areas before final assembly. The etching pattern is pre-designed to create the required thickness distribution, making the subsequent assembly process simpler and more precise.
3Ease of manufacture
If the same copper foil thickness is used for both main and control electrodes, then the production process is simplified, but the control electrode becomes wastefully thick
Solution Approach 1:
The patent resolves this contradiction by applying local quality principles: the main electrode area receives thick copper foil (0.1-0.5mm) for high current handling, while the control electrode area receives thin copper foil (0.03-0.05mm) for low current applications. This localized differentiation maintains production efficiency while eliminating material waste.
Solution Approach 2:
The patent changes the thickness parameter of the copper foil based on the functional requirements of different electrode regions. The main electrode uses thicker foil (0.1-0.5mm) to handle large currents, while the control electrode uses thinner foil (0.03-0.05mm) for signal-level currents, optimizing both material usage and electrical performance.
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
Enables efficient current application to main electrodes while preventing unnecessary thickness on control electrodes, improving heat management and production efficiency by allowing larger current flow without excessive material usage.
Implementation Method 1
The copper foil of the printed circuit board generates heat during operation of the power semiconductor module owing to current flowing from the main electrode of the semiconductor chip
Implementation Method 2
a conductive post provided with one end and another end, the one end being connected electrically and mechanically to the control electrode, and the other end being connected electrically and mechanically to the second conductive member
Data Source
AI summary
The semiconductor device includes a multi-layered substrate having an insulating plate and a circuit plate, a semiconductor chip having a front surface attached with a main electrode and a control electrode formed thereon, and a back surface fixed to the circuit plate, a first wiring substrate which includes a first conductive member and is placed so as to face the main electrode connected electrically to first conductive member, a second wiring substrate which includes a second conductive member, is placed so as to face the control electrode, and has an opening, and a conductive post having one end and another end, the one end being connected electrically and mechanically to the control electrode, and the other end being connected electrically and mechanically to the second conductive member. The first conductive member is thicker than the second conductive member, and the first wiring substrate is disposed within the opening.