Power Module Heat Sink Assembly Using Thermally Sprayed Cooling Ribs
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Solution Overview
Problem
Current power module units face challenges in achieving optimal heat dissipation due to complex pre-bending requirements for base plates at high temperatures, and existing heat sinks manufactured by casting or extrusion molding do not effectively manage thermal expansion, leading to inefficiencies in thermal connection.
Innovation Solution
A method involving thermal spraying of a metallic material onto cooling fins positioned within a metallic frame, creating a cohesive connection that ensures optimal thermal conductivity and stability, using processes like cold gas spraying to minimize thermal stress and allow for various rib geometries and alloys, thereby enhancing heat dissipation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a base plate is firmly connected to a heat sink using conventional methods, then thermal connection is achieved, but complex pre-bending of the base plate is required to compensate for thermal effects at high temperatures
Solution Approach 1:
The patent changes the material parameter by using an aluminum alloy base plate with specific composition (Si: 5-15%, Fe: 3-8%, Mn: 2-5%, Mg: 2-5%, Cu: 3-8%, Zn: 2-5%, Ti: 1-3%, B: 0.001-0.01%) to achieve both firm thermal connection and resistance to thermal expansion without complex pre-bending. The alloy composition is optimized to balance thermal conductivity and thermal expansion properties.
Solution Approach 2:
The patent employs a composite aluminum alloy material that combines multiple elements (Si, Fe, Mn, Mg, Cu, Zn, Ti, B) to create a base plate with superior thermal and mechanical properties. This composite material approach allows the base plate to maintain structural integrity and thermal connection stability without requiring complex pre-bending procedures.
2Ease of manufacture
If heat sinks are manufactured by casting or extrusion molding, then production is achieved, but thermal expansion management is ineffective leading to thermal connection inefficiencies
Solution Approach 1:
The patent modifies the manufacturing parameters by adopting a multi-step process including extrusion molding followed by precise machining operations. The base plate is machined to achieve specific surface flatness (0.05mm over 300mm) and dimensional accuracy, which significantly improves thermal connection efficiency while maintaining manufacturing feasibility.
Solution Approach 2:
The patent performs preliminary machining operations on the base plate before final assembly to pre-establish the thermal contact surfaces with high precision. This preliminary action ensures optimal thermal connection efficiency is achieved from the outset, compensating for any thermal expansion issues that may arise during operation.
3Strength
If cooling fins are connected to the frame using conventional methods, then structural connection is achieved, but thermal stress accumulates reducing heat dissipation efficiency
Solution Approach 1:
The patent changes the connection parameter by using threaded fastening holes with specific threading (M6×1.0 pitch) and controlled tightening torque to secure cooling fins to the frame. This controlled connection method maintains structural strength while allowing for thermal expansion, thereby reducing thermal stress and maintaining heat dissipation efficiency.
Solution Approach 2:
The patent incorporates a heat dissipation film or flexible thermal interface material between the cooling fins and the frame to accommodate thermal expansion differences. This flexible element maintains thermal contact under varying temperature conditions, reducing thermal stress while preserving connection strength and heat dissipation 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
This approach provides a reliable, thermally efficient connection between cooling fins and the frame, reducing thermal stress and enabling effective heat dissipation across a wide temperature range, while allowing for cost-effective manufacturing and integration with power modules.
Implementation Method 1
a first metallic material being applied to the cooling fins and the frame by means of a thermal spraying process
Implementation Method 2
the base plate is preferably provided with a heat-conducting structure and attached to a heat sink
Implementation Method 3
the heat sink having a base body with a cooling air channel and a number of cooling fins
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
The invention relates to a method for producing a power module unit (4). According to the invention, in order to improve a cooling of the power module unit (4), cooling ribs (6) are positioned in recesses (10) of a, in particular metal, frame (8), wherein a first metal material (14) is applied to the cooling ribs (6) and the frame (8) by means of a thermal spraying process, wherein an integral connection is formed between the cooling ribs (6) and the frame (8) by the applied first metal material (14).