Additive Manufacturing is Taking Off
This year has seen a fast adoption of new additive manufacturing techniques in the electronics industry. These techniques are mostly 3D printing processes but others, such as ultrasonic bonding, have also been adopted. In the October issue of Microwave Journal, the cover story is about work being done at the MITRE Corporation to investigate a new generation of 3D printing techniques and materials to realize complex geometries for wideband phased array and metamaterial designs using low-cost, commercial desktop printers. They have demonstrated the technology by making 3D printed monopole Wi-Fi antennas and are now working on a complex, electrically-functional phased array and metamaterial structure. All of this is being done with a commercially available desktop 3D printer from Voxel8 who is working closely with MITRE on the project.
In our August Fabs and Labs article, we covered the Printed Electronics Research Collaborative at University of Massachusetts Lowell where they are using 3D printers to manufacture frequency selective surfaces, antennas, waveguides, phased arrays and even tunable devices printed on plastic materials. They use conductive plastics as a seed material for electroplating, selectively plating areas on complicated geometries by printing the conductive plastic only on the areas to be plated and using normal non-conductive plastics for the other areas. Researchers there are the first to develop a ferroelectric ink that enables varactors to be printed onto their circuits for tunable applications such as frequency selective surfaces and phased arrays. Raytheon and other companies are sponsors of the collaborative and closely involved in their projects and research.
Another example is NanoDimensions’3D-printed PCBs and circuits that could make their way into the high frequency market soon. Nano Dimension's 3D printer is an inkjet deposition and curing system for printing multilayer circuit boards. Their conductive silver nano inks for electronics printing are available with the system that enables rapid prototyping capabilities for custom PCB prototyping including the flexibility to print an entire board or just part of a circuit. Engineers can develop the RF and digital sections of the board in parallel, test and iterate quickly.
Pulse Electronics recently released a 3D printer that uses conductive inks to produce high-performance antennas, sensors, and electrical circuits on 3D surfaces. The system uses affordable micron particle inks to print on standard plastic substrates that have robust mechanical properties, enables new integration possibilities, and extends industrial design flexibility and materials options. This technology delivers significant cost savings potential from rapid prototyping and versioning of designs.
For metal products, there are 3D printers available that produce metal structures typically be sintering 3D printed metal powders with laser heating or baking. MDL is using 3D metal printers to manufacture complicated waveguide parts such as rotary switches. This avoids the expensive process of making a mold for casting the metal parts which is especially cost effective if only low volumes are needed. They can also take a CAD drawing and quickly make a plastic part to manufacture the casting mold without having to machine the part so it reduces time and cost.
Ultrasonic additive manufacturing is another possible revolutionary process technology that uses sound to merge layers of metal drawn from featureless foil stock. The process produces metallurgical bonds with full density and works with a variety of metals. Because it is done a relatively low temperature (compared to the melting point), it protects material properties of the incoming feedstock, bonds dissimilar metals without creating brittle inter-metallic materials, and enables embedded electronics in solid metal parts. Fabrisonic is a company very active in this technology which could change the way we manufacture metal components.
The future of additive manufacturing will be very interesting to follow over the next few years. The technology will change the way we manufacture circuits and will be especially useful in rapid proto-typing since designs can be made very quickly at a low cost with iterations done in hours instead of days or weeks. Let me know what other examples of additive manufacturing you have seen that look interesting.