Power Device Insulating Member Force Dispersion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional power devices face issues with substrate breakage due to applied forces during heat and power cycles, leading to metal fatigue and reduced functionality, particularly when solder is used to connect electrodes, as it can cause stress and cracking at the substrate level.
Innovation Solution
A power device design featuring a first and second main electrode on opposite surfaces of a substrate, with a low-adhesion insulating member between metal layers to disperse applied forces, reducing the likelihood of substrate breakage by minimizing force transmission to the substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If solder is joined to the upper surface electrode to increase current flow, then the current carrying capacity is improved, but the substrate may break when large force is applied to the additional electrode
Solution Approach 1:
A protective layer is introduced as an intermediary between the additional electrode and the surface electrode. This protective layer absorbs and disperses the force applied to the additional electrode, preventing it from being directly transmitted to the substrate. The protective layer acts as a mediator that protects the substrate from breakage while allowing the solder connection to maintain its current carrying capacity.
Solution Approach 2:
The protective layer is positioned beforehand between the additional electrode and the surface electrode to cushion against future force applications. This pre-positioned protective structure prepares the system to withstand large forces that may be applied during operation, preventing substrate breakage before it occurs.
2Adaptability or versatility
If multiple members are joined together to form the power device, then the functionality is improved, but large force is applied to the joined portions due to differential thermal expansion
Solution Approach 1:
The protective layer serves as an intermediary at the joined portion between the additional electrode and the surface electrode. This intermediary structure accommodates the differential thermal expansion between different members by absorbing expansion forces, thereby reducing the stress transmitted to the joined portions while maintaining the overall functionality of the power device.
3Stability of the object's composition
If the protective layer adheres to both the additional electrode and the surface electrode, then the connection stability is improved, but the force is transferred to the substrate when large force is applied
Solution Approach 1:
The adhesive properties of the protective layer are optimized to achieve a balance: the protective layer adheres sufficiently to both the additional electrode and the surface electrode to maintain connection stability, but the adhesion strength is controlled so that when large force is applied, the protective layer deforms or fails before the substrate breaks. This parameter optimization allows the protective layer to absorb force while maintaining normal connection stability during operation.
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 design effectively disperses applied forces along the connection plane between metal layers, thereby minimizing the risk of substrate breakage and improving heat and power cycle resistance, enhancing the device's durability and reliability.
Implementation Method 1
The insulating member is structured so that the first end of the first metal layer is partially connected to the second end of the second metal layer
Data Source
AI summary
A first metal layer is provided on a main surface side of a substrate. A second metal layer is formed on the first metal layer. A solder layer is provided on the second metal layer. An insulating member is structured so that an end of the first metal layer is partially connected to an end of the second metal layer.