Crimping Power Module Elastic Buffer for Substrate Fracture
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current crimping power modules face limitations due to fragile electric insulation substrates, which restrict the design of high-power modules and lead to increased thermal resistance due to thermal grease layers and mismatched coefficients of heat expansion between chips and substrates.
Innovation Solution
A crimping power module design featuring an annular slot in the shell with a first elastic member that provides a flexible crimping mechanism, allowing adjustable pressure and reducing the risk of substrate fracture, while minimizing the thermal grease layer thickness to enhance thermal efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a hard crimp connection is adopted between the shell and electric insulation substrate, then the structural strength is improved, but the electric insulation substrate is vulnerable to fracture and the power rating is limited
Solution Approach 1:
The patent introduces an elastic member (rubber ring or spring) between the shell and electric insulation substrate to replace the traditional hard crimp connection. This flexible element allows the shell to elastically deform during crimping, distributing the compression force uniformly across the substrate surface and preventing localized stress concentration that would cause fracture. The elastic member acts as a cushion, enabling reliable connection while maintaining substrate integrity for high-power applications.
Solution Approach 2:
The patent changes the mechanical properties of the connection system by introducing an elastic member with specific material properties (elastic modulus, damping characteristics). This allows the connection to transition from a rigid, high-stress state to a flexible, stress-distributing state. The elastic member's deformation characteristics enable the system to accommodate thermal expansion differences while maintaining reliable electrical and thermal contact.
2Power
If the surface area of the electric insulation substrate is increased to support higher power, then the power rating is improved, but the substrate becomes more vulnerable to breaking during crimping
Solution Approach 1:
The elastic member provides a flexible connection mechanism that distributes crimping stress across the entire surface area of the substrate. This allows the substrate to be designed with larger surface area for high-power applications without increasing vulnerability to fracture, as the elastic member prevents stress concentration at any single point during the crimping process.
3Reliability
If thermal grease layer thickness is increased to accommodate substrate deformation, then the substrate fracture risk is reduced, but the thermal resistance increases and thermal efficiency decreases
Solution Approach 1:
The elastic member absorbs substrate deformation through its own elastic compliance, eliminating the need to increase thermal grease layer thickness for accommodation. This maintains minimal thermal grease thickness, keeping thermal resistance low while still protecting the substrate from fracture through the elastic member's stress-distributing mechanism.
4Device complexity
If the coefficients of heat expansion mismatch between chips and substrate is not addressed, then the manufacturing process is simple, but thermal grease layer increases and thermal efficiency decreases
Solution Approach 1:
The elastic member's compliance allows it to accommodate thermal expansion mismatches between chips and substrate during temperature cycles. This elastic accommodation mechanism maintains consistent thermal contact without requiring complex compensation structures or increasing thermal grease thickness, thus preserving thermal efficiency while managing expansion differences.
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 solution enables the creation of high-power modules with improved thermal conductivity and efficiency by preventing substrate fracture and optimizing the pressure distribution, thus overcoming the limitations of fragile substrates and thermal resistance issues.
Implementation Method 1
The annular slot is embedded with a first elastic member for being elastically abutted against the electric insulation substrate. The first elastic member extends out of the second surface of the shell, to allow the shell to adjust a pressure flexibly crimped to the heat dissipation device by the electric insulation substrate.
Implementation Method 2
the pressure flexibly applied on the heat dissipation device by the electric insulation substrate can be adjusted through controlling the compression height or degree of the elastic member. Therefore, the electric insulation substrate can be firmly crimped to the heat dissipation device, and a thickness of a thermal grease layer between the electric insulation substrate and the heat dissipation device can be decreased
Data Source
AI summary
A crimping power module includes a shell (10), a cover (12), and an electric insulation substrate (13) crimped to a heat dissipation device. The cover and the substrate are respectively mounted to a first surface (111) and a second surface (112) of the shell. The second surface defines an annular slot (113) in a position facing sides of the substrate. The slot is embedded with a first elastic member (15) elastically abutted against the substrate. The elastic member is higher than the second surface, allowing the shell to adjust a pressure flexibly applied on the heat dissipation device by the substrate. An elastic buffer is provided through defining the slot embedded with the elastic member, to prevent the substrate from fracturing, and adjust the pressure to ensure tight crimping between the substrate and the heat dissipation device, which decreases thermal resistance, and increases heat dissipation efficiency.