Laser Structuring Power Electronic Modules to Reduce Thermomechanical Stresses
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Solution Overview
Problem
Power electronic modules face thermomechanical stresses due to differing coefficients of thermal expansion, leading to deformation and reduced service life, which existing methods like etching struggle to address effectively.
Innovation Solution
The method involves using a laser beam for local material removal to structure the power electronic circuit carrier, metallisation, and base plate, allowing for precise reduction of thermomechanical stresses and enhancement of electrical functionality by creating fine structures such as depressions and conductor tracks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If etching methods are used to structure the circuit carrier, then thermomechanical stresses are reduced, but manufacturing precision and fine structuring capability are limited
Solution Approach 1:
The patent replaces chemical etching methods with laser beam processing to structure the circuit carrier and metallisation. The laser beam enables precise material removal with controlled depth and geometry, creating fine structures such as recesses and grooves that significantly reduce thermomechanical stresses while maintaining electrical functionality. This substitution of mechanical/thermal processing for chemical etching achieves superior manufacturing precision and structuring capability.
Solution Approach 2:
The patent utilizes laser beam parameters (power, pulse duration, scanning speed, wavelength) to precisely control the structuring process. By adjusting these parameters, the laser can create different structures (recesses, grooves, patterns) with varying depths and geometries, enabling optimization of stress reduction while maintaining manufacturing precision. The laser parameters are tuned to achieve selective material removal without damaging surrounding areas.
2Reliability
If laser beam structuring is applied to reduce thermomechanical stresses, then service life is extended, but manufacturing complexity increases
Solution Approach 1:
The laser beam processing system serves multiple functions: it structures the circuit carrier to reduce stresses, creates precise conductor tracks, forms recesses for component mounting, and can modify metallisation patterns. This multi-functionality consolidates multiple manufacturing steps into a single versatile process, reducing overall manufacturing complexity despite the advanced technology involved.
Solution Approach 2:
The laser beam processing is performed in-situ during the manufacturing process, eliminating the need for separate structuring operations. The same laser system that welds or bonds components can also structure the circuit carrier and create conductive paths, allowing the manufacturing system to perform multiple tasks without additional equipment or process steps.
3Reliability
If metallisation is structured to enhance electrical functionality, then electrical performance is improved, but thermomechanical stresses may increase
Solution Approach 1:
The patent applies selective structuring to the metallisation layer, creating different structures in different regions based on local requirements. Conductor tracks are precisely formed where electrical connectivity is needed, while recesses are created in specific areas to reduce stresses. This local differentiation allows simultaneous optimization of electrical functionality and stress distribution without compromising either aspect.
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 significantly extends the service life and improves electrical functionality of power electronic modules by reducing thermomechanical stresses and enabling precise structuring that previous methods cannot achieve, such as creating shielding and precise conductor tracks.
Implementation Method 1
the power electronic circuit carrier, and/or the metallisation applied onto the power electronic circuit carrier, and/or a base plate connected, or to be connected, to the rear face of the power electronic circuit carrier, is structured by means of local material removal with at least one laser beam
Data Source
AI summary
In a method for increasing the electrical functionality, and/or service life, of power electronic modules, the power electronic circuit carrier, and/or the metallisation applied onto the power electronic circuit carrier, and/or a base plate connected, or to be connected, to a rear face of the power electronic circuit carrier, is finely structured by means of local material removal with at least one laser beam, so as to reduce thermomechanical stresses occurring during the production or operation of the module. In an alternative form of embodiment, the metallisation applied onto the front face of the power electronic circuit carrier is structured, or an already created structure is refined or supplemented, by means of local material removal with laser radiation, so as to achieve a prescribed electrical functionality of the metallisation.