Power Module Thick-Film Copper Layout Without Etching Undercuts
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Solution Overview
Problem
Existing electronic modules with thick copper substrates face challenges in cost-effectiveness and manufacturing efficiency due to time-consuming etching processes and potential undercuts, which can lead to mechanical stress and electrical breakthroughs, while traditional methods for producing thick conductor tracks are expensive and difficult to scale.
Innovation Solution
The use of thermally and electrically conductive elements with a cohesive connection, such as solder or sintered connections, to form a thick layer with a thickness of at least 0.5 millimeters, allowing for efficient heat dissipation and flexible construction without undercuts, using subtractive manufacturing methods like laser cutting and water jet cutting, and a thin thermally conductive material to achieve comparable heat spreading properties to a single block layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If thick copper substrates are structured using etching processes, then the copper thickness can be reduced, but the etching time increases significantly and undercuts occur leading to potential electrical breakdowns
Solution Approach 1:
The patent applies preliminary action by pre-structuring the thick copper substrate using milling or water jet cutting before etching. This removes the majority of the copper thickness (e.g., 1.9mm out of 2mm) in advance, so that only a thin remaining layer (e.g., 0.1mm) needs to be removed by etching. This dramatically reduces etching time from hours to minutes while avoiding undercut formation, as the etchant only needs to penetrate a minimal depth.
Solution Approach 2:
The patent segments the copper removal process into two distinct stages: mechanical removal (milling or water jet cutting) and chemical removal (etching). This segmentation allows each process to be optimized independently - mechanical methods handle bulk material removal efficiently, while etching provides precise final structuring without the time and quality problems of using etching alone on thick substrates.
2Manufacturing precision
If thick copper substrates are structured using milling, then etching time is reduced and undercuts are avoided, but production time increases due to additional cleaning steps
Solution Approach 1:
The patent replaces the mechanical milling process with a water jet cutting process for the preliminary structuring step. Water jet cutting uses a high-pressure stream of water (often mixed with abrasives) to erode and remove material without mechanical contact. This eliminates the need for subsequent mechanical cleaning steps required after milling, as water jet cutting leaves a cleaner surface that requires minimal or no additional cleaning, thus improving productivity while maintaining the benefits of reduced etching time and avoided undercuts.
3Ease of manufacture
If conventional etching is used on thick metal layers, then the process can be simple, but safety issues arise and costs increase
Solution Approach 1:
By performing preliminary mechanical or water jet structuring before etching, the patent reduces the copper thickness that needs to be removed by etching from several millimeters to a fraction of a millimeter. This dramatically reduces the amount of hazardous etching chemicals required and the time they are in use, thereby maintaining process simplicity while significantly improving safety and reducing costs associated with chemical handling, disposal, and safety infrastructure.
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 enables the production of electronic modules with enhanced heat dissipation and robustness while reducing manufacturing time and costs, eliminating undercuts and ensuring safety, thus improving the adaptability and efficiency of industrial systems.
Implementation Method 1
the thermally conductive material, preferably by a metallurgical bond... the thermally conductive material has a thermal conductivity of at least 20 mW/mK... enables efficient heat dissipation... lateral thermal conductivity and consequently high heat spreading
Implementation Method 2
lateral thermal conductivity and consequently high heat spreading... the thermally conductive material has a thermal conductivity of at least 20 mW/mK... exhibits almost identical overall thermal properties as a similarly dimensioned thick film manufactured from a single block
Data Source
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AI summary
The electronic module is, in particular, a power module, and has a circuit carrier which has at least one electrically conducting thick film with at least a thickness of at least 0.5 millimetre, preferably at least 2 millimetres and ideally at least 4 millimetres. The electrically conducting thick film has a plurality of electrically conductive elements which are connected to one another, which elements are connected to one another by means of an electrically conductive material. The industrial plant has a control device, in particular for controlling a motor and/or generator preferably of the industrial plant. The control device of the industrial plant according to the invention comprises at least one electronic module of this type.