Power Module Encapsulation With Welded Sealing Ring Cooling
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Solution Overview
Problem
Existing methods for encapsulating power modules and coolers face challenges in forming a reliable sealed fluid path, as they often result in local leakage due to aging sealing rings or deformation, leading to risks of electrical short circuits and reduced sealing reliability.
Innovation Solution
The encapsulation structure and method involve overlapping the power module body on a groove of the cooler, with a metal baseplate protrusion forming a welded sealing ring through front and back welding, eliminating the need for a sealing ring and enhancing sealing reliability by creating a complete sealed fluid path.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a sealing ring is added between the power module and the cooler, then the sealing reliability deteriorates due to aging and deformation, but the ease of manufacture improves as it provides a simple sealing solution
Solution Approach 1:
The patent removes the sealing ring component entirely from the encapsulation structure. Instead of using a separate sealing ring that degrades over time, the sealing function is integrated directly into the metal baseplate through laser-welded sealing rings formed on its peripheral surface, eliminating the aging and deformation issues associated with traditional sealing rings
Solution Approach 2:
The patent combines the sealing function with the metal baseplate structure itself. The sealing ring is welded directly to the peripheral surface of the metal baseplate, merging the support structure and sealing elements into a single integrated component, thereby eliminating the need for separate sealing rings that can degrade
2Manufacturing precision
If local high-energy heating is performed by using a laser beam to establish a welding pool, then the manufacturing precision improves for localized welding, but the device complexity increases due to optical path interruptions from power pins
Solution Approach 1:
The patent transitions from two-dimensional planar welding to three-dimensional multi-angle welding. By forming sealing rings on the peripheral surface of the metal baseplate and performing welding from multiple directions (front and back sides), the laser can access welding positions without being blocked by power pins, maintaining precision while reducing optical path complexity
Solution Approach 2:
The patent divides the welding process into multiple segments performed from different directions. Instead of attempting a single continuous laser pass that would be blocked by power pins, the sealing is achieved through segmented welding operations on the peripheral surface, allowing each segment to be accessed independently by the laser beam
3Productivity
If the power module and cooler are sealed through welding or sealing and crimping, then the productivity improves by forming a complete encapsulation, but the reliability deteriorates due to gaps and leakage from aging components
Solution Approach 1:
The patent employs a composite structure combining the metal baseplate with laser-welded sealing rings formed on its peripheral surface. This composite approach integrates the structural support function of the metal baseplate with the sealing function of the welded rings, creating a unified encapsulation structure that maintains both productivity and long-term reliability without aging-related degradation
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 improves the sealing reliability and heat dissipation performance of the power module by forming a complete sealed fluid path between the power module and cooler, reducing the risk of leakage and electrical short circuits while simplifying the welding process.
Implementation Method 1
Local high-energy heating is performed by using a laser beam, to establish a welding pool and a welding region
Implementation Method 2
a welded sealing ring is formed through laser welding
Data Source
Figure 1~2A
Figure 2B~3A
Figure 3B~3C
AI summary
Embodiments of this application disclose an encapsulation structure and an encapsulation method of a power module, applied to the automotive field. The encapsulation structure includes a power module and a liquid cooler. The power module includes a power module body, a metal baseplate, and heat dissipation finned tubes. A front side of the metal baseplate is connected to the power module body, and a back side of the metal baseplate is connected to the heat dissipation finned tubes. The metal baseplate has a protrusion part protruding from the power module body. There are a plurality of grooves on a fluid pipe of the liquid cooler, a cavity exists between two adjacent grooves of the plurality of grooves, and the cavity is configured to communicate the two adjacent grooves. The power module body is lapped on the groove, a back side of the protrusion part is in contact with an edge surface of the groove, and the heat dissipation finned tubes are placed in the groove. A front weld exists on a front side of the protrusion part, and a back weld exists on the back side of the metal baseplate other than the back side of the protrusion part; and the front weld and the back weld form a welded sealing ring.