Metal Foam Pressure Element for Homogeneous Clamping Force
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing clamping assemblies for stacked components suffer from non-homogeneous pressure distribution, which can lead to damage, especially for thin and brittle semiconductor chips, and fail to effectively dampen vibrations in high-voltage applications.
Innovation Solution
A clamping assembly utilizing a pressure element made of metal foam material with controlled elastic properties, allowing for a homogeneous pressure distribution and enhanced vibration damping, achieved through the use of metal foam materials with varying moduli of elasticity and a spatial arrangement that increases stiffness from the inside to the outside, along with a pressure counter-element for improved force transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If conventional pressure plates and clamping screws are used to generate compressive force, then the clamping assembly can mechanically hold stacked components, but the pressure distribution becomes non-homogeneous with significantly higher pressure at the central axis compared to edge regions
Solution Approach 1:
The patent employs a pressure element made of metal foam material with controlled porosity (50-90% volume fraction of pores). The porous structure allows the material to deform and distribute compressive forces more uniformly across the clamped components, eliminating the non-homogeneous pressure distribution caused by conventional solid pressure plates. The pore structure enables lateral expansion under compression, transferring force more evenly to edge regions.
Solution Approach 2:
The patent changes the physical parameters of the pressure element by using metal foam with specific density ranges (0.1-5 g/cm³) and controlled pore characteristics. By adjusting the porosity and density parameters, the pressure element achieves optimal compliance to distribute pressure homogeneously while maintaining sufficient load-bearing capacity. This parameter optimization resolves the contradiction between force transmission and pressure distribution.
2Strength
If solid pressure plates are used for clamping, then structural strength is maintained, but vibration damping capability is insufficient with damping properties only 1/2 to 1/3 of metal foam material
Solution Approach 1:
The metal foam material's porous structure provides superior vibration damping through energy dissipation mechanisms within the pore network. The interconnected pores create friction and hysteresis effects that dampen vibrations effectively, achieving 2-3 times better damping performance than solid materials while maintaining adequate structural strength for the application.
Solution Approach 2:
The patent uses metal foam as a composite material combining metallic strength with porous damping characteristics. This composite structure integrates the beneficial properties of both solid metals (strength) and porous structures (damping), resolving the contradiction between maintaining structural integrity and providing effective vibration damping.
3Stress or pressure
If pressure elements are designed for specific component sizes, then optimal pressure distribution is achieved for those components, but the design cannot be scaled to accommodate components of different sizes
Solution Approach 1:
The metal foam pressure element provides universal applicability across different component sizes due to its scalable geometry and self-adjusting pressure distribution characteristics. The foam structure can be manufactured in various sizes while maintaining the same homogeneous pressure distribution property, making it adaptable to different application scales without redesigning the fundamental pressure distribution mechanism.
Solution Approach 2:
The patent enables scaling by changing the geometric parameters of the metal foam pressure element (size, shape, porosity) while maintaining the fundamental pressure distribution mechanism. The material's inherent ability to distribute pressure homogeneously is preserved across different scales through appropriate selection of foam density and pore structure parameters.
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 ensures a homogeneous pressure distribution, reduces the risk of component damage, and provides effective vibration damping, making it suitable for components of any size and applications in high-voltage technology.
Implementation Method 1
Through the use of the pressure element containing the metal foam material, the additional effect of damping vibrations of the arrangement can be achieved. In comparison to a solid material, the damping properties of the metal foam material can be higher by a factor of 2-3.
Implementation Method 2
Through the use of the metal foam material, whose elastic properties can be selectively controlled and influenced through appropriate manufacture, a relatively homogeneous pressure distribution in the transmission of the compressive forces to the arrangement of the components can be achieved.
Data Source
AI summary
A clamping assembly includes a configuration of mechanically clamped components disposed one on top of the other to form a stack. A clamping device generates a mechanical compressive force on the configuration of the components and a pressure element transmits the mechanical compressive force from the clamping device to the configuration. The pressure element contains a metal foam for a planar, homogeneous transmission of the compressive force. A sub module of a converter having at least one series circuit of power semiconductor switching units implemented as the clamping apparatus is also provided.