A lack of standards means designers need to rely on vendor datasheets and enable out-of-the-box thinking.
The additive manufacturing electronics (AME) industry is rapidly gaining momentum, with the market size projected to reach billions in the coming years as engineers and designers increasingly adopt this cutting-edge technology. Despite the growing use of technology, educational resources and design guidance for AME remain scarce, leaving many professionals to navigate uncharted territory. To bridge this gap, here are five essential tips every designer should know when creating electronic circuits using AME.
1. Material compatibility. It is essential for engineers to consult material datasheets early in the design process and adjust calculations accordingly. AME relies on materials that differ from those used in traditional PCB fabrication. Our signature machine utilizes silver nanoparticle ink for conductive elements such as traces and ground (GND) planes, coupled with an acrylate-based photopolymer for dielectric layers and structures, instead of relying on copper traces and fiberglass-reinforced laminates. These differences have important implications for both mechanical and electrical design.
Mechanically, traditional laminates offer high strength due to glass-fiber reinforcement. In contrast, AME photopolymers are composed entirely of polymer, making them inherently less rigid. Since most AME applications focus on electronic rather than mechanical performance, however, this is rarely a limitation, and designers can compensate for the reduced material strength by optimizing the part’s geometry. Compact, well-structured designs often exhibit excellent durability, even in demanding environments, thanks to favorable aspect ratios and the precision of micron-scale printing.
Electrically, the materials used in AME also exhibit different behavior. For example, the dielectric constant of our photopolymer is approximately 2.8, compared to the 3.8 to 4.4 range typical of FR-4 substrates. Consider the lower dielectric constant when designing for AME, where impedance control is required. Additionally, the 3-D capabilities of AME enable out-of-the-box thinking and the implementation of various transmission lines, such as embedded coaxial lines, which are difficult to fabricate using traditional manufacturing methods. These factors can significantly affect designs.
As the AME field evolves, a broader selection of materials will become available, offering greater flexibility in terms of dielectric constants, conductivity and mechanical performance. This will open new possibilities for designers seeking to push the boundaries of electronic circuit design (Figure 1).
Figure 1. A 3-D printed PCB.
2. Populating boards. The thermal properties of AME support lower-temperature soldering processes. For example, the silver nanoparticle ink used in our systems permits solder reflow at around 200°C, compared to the 240°C typically required in traditional PCB assembly.
AME also introduces a unique capability beyond surface mounting: the ability to embed components directly within the printed structure. This is achieved by pausing the print mid-process, placing the component into a predesigned cavity, and then continuing the print to secure it and print its interconnect. This approach can eliminate the need for soldering or wire-bonding if the silicon die is placed altogether.
Embedding components requires a shift in design thinking, however. Instead of working in two dimensions, designers must consider the full three-dimensional structure of the circuit. This includes planning for internal cavities, vertical interconnects, and ensuring that embedded components can withstand the UV curing and thermal conditions of the printing process. For example, researchers at the Technical University of Liberec successfully embedded a thin ferromagnetic core into a 3-D-printed coil to create a fluxgate sensor using this method, resulting in superior performance. This approach achieved higher sensitivity and lower noise levels than otherwise would be possible, making it suitable for precise magnetic field measurements.
3. Following the design rules. While AME eliminates the need for traditional milling and drilling, it still requires adherence to specific design rules to ensure manufacturability and performance. These rules govern aspects such as trace width, spacing between conductive elements, and the geometry of embedded structures.
In traditional PCB fabrication, design constraints are largely dictated by the mechanical limitations of the manufacturing equipment. In AME, the constraints are defined by the resolution of the printing process and the behavior of the materials during the curing process. For example, we typically recommend a minimum trace width and spacing of 6 mils (0.006"). These values ensure reliable electrical performance and prevent issues such as short circuits or signal degradation.
Figure 2. A 3-D printed flexible circuit.
Designers also need to consider the integration of dielectric structures for placing components with mechanical holding, or passive electrical devices embedded onto the board. This includes capacitors, inductors and transmission lines for radio frequency (RF) applications, such as coaxial lines or waveguide structures. Regardless of the integrated element, each of these elements must be designed within the resolution limits of the printer and the electrical characteristics of the materials.
4. Optimizing print time. For AME, there are also best practices around placing the device on the printing tray, as good orientation is essential to optimize print time. Suboptimal placement will require more passes to build up each layer. The total height of the device also affects printing time, so the lower the profile, the faster the print, as layer thickness for the dielectric material is ~5-10µm, depending on the material in use, and ~1µm for the conductive material. Although this level of accuracy takes time to print, it enables highly accurate printing and designs that wouldn’t otherwise be possible, offering custom thicknesses, as opposed to traditional laminates, which come in specific thicknesses.
In AME, print time is influenced not only by the design complexity but also the part orientation on the print tray. Strategic placement can significantly reduce the number of passes required to build each layer, directly impacting overall production time. Orientation also plays a critical role. Aligning the design to minimize the number of print head movements can lead to more efficient builds.
The height of the printed object is a key factor. Since dielectric layers are deposited at 5 to 10µm per pass and conductive layers at just ~1µm, taller structures naturally take longer to fabricate. By minimizing the vertical profile where possible, designers can accelerate the build process without compromising functionality (Figure 3). By considering these factors early in the design phase, engineers can fully leverage of AME’s efficiency.
Figure 3. Complex high-layer-count PCBs can be easily produced with the right additive manufacturing system.
5. Reliability, standardization and testing. Unlike traditional PCB manufacturing, AME currently operates without a unified set of industry standards. While organizations such as IPC are actively developing guidelines for additive electronics, designers today must take a more tailored approach to testing and validation.
In conventional PCB production, standard tests – such as thermal cycling, humidity exposure and vibration – are applied uniformly, regardless of the end application. These tests simulate long-term use and environmental stress, ensuring reliability across a wide range of conditions. In AME, however, the lack of standardized benchmarks means that testing must be customized to the specific use case of the printed device.
For example, thermal cycling from –20° to 120°C is common for evaluating electronic components. In AME, devices such as interposers, antennas or embedded connectors may pass without issue, while others may require design adjustments to meet performance expectations. The results can vary significantly depending on the design’s geometries.
As the AME ecosystem matures, the development of formal standards will simplify this process, enabling more consistent testing and certification. In the meantime, designers must remain proactive, defining test protocols based on the intended application and staying informed about emerging guidelines from industry bodies.
Putting AME into Practice
As additive manufacturing electronics continue to evolve, it offers designers unprecedented flexibility. Nevertheless, realizing the full potential of AME requires a solid understanding of its unique materials, design constraints and process considerations. By adapting design approaches and staying informed about emerging materials, technologies and standards, engineers can confidently leverage AME to create innovative, high-performance electronic systems that go beyond the limitations of traditional manufacturing.
Amir Shelef is application engineering director, AME, at Nano Dimension (nano-di.com), a provider of micro-3D printing/additive manufacturing (AM) solutions for a diverse array of applications spanning industry sectors such as medical, aerospace, automotive, consumer, electronics, optics and semiconductors; This email address is being protected from spambots. You need JavaScript enabled to view it..
