Crossed Bonding Wire Layout for Power Module Fatigue Relief
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Bonding wires in power modules are prone to fatigue due to fluctuating stress, affecting their reliability and service life, particularly in high-power density applications where electromagnetic forces between wires are significant.
Innovation Solution
The bonding structure employs spatial cross wire bonding, where lead paths of bonding wires form angles with each other, creating intersection points on a preset plane to weaken electromagnetic forces, thereby alleviating stress and prolonging the service life of the wires.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If bonding wires are arranged in a traditional parallel or planar configuration, then the electrical connection is simple to implement, but the electromagnetic force between adjacent wires causes fatigue due to fluctuating stress
Solution Approach 1:
The patent transitions from a two-dimensional planar wire arrangement to a three-dimensional spatial cross configuration. The bonding wires are arranged to cross each other in space, forming a cross-shaped pattern where wires extend in perpendicular directions (e.g., one wire along the x-axis, another along the y-axis). This dimensional change increases the separation distance between adjacent parallel wire segments, thereby reducing electromagnetic coupling and fluctuating stress while maintaining electrical connectivity.
2Power
If bonding wires are placed close together to reduce packaging size, then the power density increases, but the electromagnetic force between wires increases causing wire fatigue
Solution Approach 1:
By arranging wires in a three-dimensional cross configuration rather than parallel planes, the patent reduces the effective parallel length and separation distance between adjacent wires. The cross-shaped arrangement ensures that wire segments intersect at right angles, minimizing the parallel proximity that generates electromagnetic force while maintaining compact packaging dimensions.
Solution Approach 2:
The patent employs asymmetric spatial positioning of bonding wires in a cross configuration, where wires are strategically placed at different heights and angles rather than symmetric parallel arrangements. This asymmetric layout optimizes the separation between current-carrying paths, reducing electromagnetic coupling while maintaining electrical performance and power density.
3Reliability
If traditional wire leading methods are used, then the packaging process is simple, but the bonding wires are prone to fatigue due to fluctuating stress
Solution Approach 1:
The patent implements spatial cross wire bonding that requires three-dimensional positioning and crossing of wires at specific angles and heights. This dimensional complexity increases the difficulty of the bonding process compared to traditional planar arrangements, as it requires precise control of wire trajectories in multiple dimensions to achieve the cross configuration that reduces electromagnetic stress.
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 approach enhances the reliability and service life of bonding wires by reducing fatigue caused by electromagnetic forces, ensuring a robust bonding effect.
Implementation Method 1
spatial cross wire bonding is performed on bonding wires, so that lead paths of the bonding wires form an angle with each other, thereby weakening electromagnetic force between the bonding wires
Data Source
Figure 1~4
Figure 5~8
Figure 9~12
AI summary
Embodiments of this application provide a bonding structure and a power device. The bonding structure includes a first power unit and at least two bonding wires. At least one end of the bonding wire is connected to the first power unit through bonding. Projections that are of lead paths of the at least two bonding wires and that are on a preset plane have at least one intersection point. In this application, spatial cross wire bonding is performed on the bonding wires, so that lead paths of the bonding wires form an angle with each other, thereby weakening electromagnetic force between the bonding wires. Therefore, fatigue due to fluctuating stress of the bonding wires can be alleviated, service lives of the bonding wires can be prolonged, and bonding effect can be ensured to a maximum extent.