3D metal printing for power electronics

Modern electronics require ever smaller components, resulting in a higher power density with the same efficiency in a smaller space. This is a major challenge for conventional heat sinks, as their own structures require a lot of space, but at the same time they have to dissipate an increasing amount of heat. "For this reason, we have developed a 3D metal printing process with a powder bed that can be used to produce microcoolers in any shape," reports Dr. Thomas Ebert, Managing Director of IQ evolution. "The heat sinks produced with our selective laser melting process dissipate enormous amounts of heat in the smallest of spaces."

Selective laser melting can also be used to produce heat sinks with unusual structures. © IQ Evolution

"First, a CAD model of the component is created for the SLM. Thanks to their experience in the field of thermodynamics, our experts quickly identify the critical hotspots and can set the required values," says Ebert. Conventional heat sinks use finned structures, whereas with microcoolers the heat is dissipated via highly turbulent flows created by special design parameters on the inner surfaces. A computer simulation supports the selection of the necessary parameters, whereby the mechanical properties such as turbulence or flow velocity are transferred 1:1 from development to production.

Once the model has been created, the metal powder is applied to a substrate plate in layers of around 0.03 mm in an insulated chamber. Nickel powder is usually used for this. Depending on the application, however, other metals or copper alloys can also be used.

Dr. Thomas Ebert, Managing Director of IQ Evolution. © IQ Evolution

IQ evolution tailors each microcooler to the area of application. "We offer standard products for common applications; so-called 2, 4 or 8-piece coolers. But the specialty of our 3D printing process is unusual cooling structures," says Ebert. "Unfortunately, power electronics are often only thought of in two-dimensional shapes, but round or even more unusual space-saving geometries are also conceivable." These flexible design variants open up numerous new application possibilities - for example, ultra-thin microcoolers that are integrated into a circuit board during production.

Thanks to years of expertise in thermodynamics, the experts at IQ Evolution can quickly identify the critical hotspots and set the required parameters for the cooling structure. © IQ Evolution

The process can also be carried out with different materials. This also results in new functions for the microcoolers. "In power electronics, electrical contact with the metal surface of the microcooler is often undesirable," explains Ebert. "We have therefore developed a combination of electrical insulation and electrically conductive layers, which are applied to the metal cooling surface. This means that all hotspots on the circuit board are cooled, but at the same time the microcooler is not electrically connected to the circuit board."

According to documents from IQ evolution / ag