About 30 years ago, 3D printing began as a technology for rapid prototyping, allowing designers, engineers and manufacturers to quickly produce physical mockups of their designs. As 3D printing matures, however, it's growing into a method for actually manufacturing end parts in a wide variety of materials and across industries.
Similarly, Israeli firm Nano Dimension has entered the manufacturing space with a technology capable of rapidly prototyping multilayered printed circuit boards (PCBs). At the moment, although not yet commercially released, the DragonFly 2020 3D printer can 3D print PCBs so that engineers and manufacturers can iterate circuit board concepts more quickly and affordably than they would through traditional methods. In the future, however, it's easy to imagine this technology evolving to 3D print end parts—in this case, fully functional electronic devices.In an interview with ENGINEERING.com, Simon Fried, CBO of Nano Dimension, spoke as to the company’s technology, where it’s heading and the benefits he sees PCB 3D printing bringing to the manufacturing industry right now.
What Does It Take to 3D Print a Circuit?
In speaking with Fried, it became clear that the DragonFly 2020 really is a 3D printing platform, but one that has been specialized for the 3D printing of PCBs. The system deposits inks similarly to inkjet 3D printers on the market. While one of these inks is still a photopolymer, as seen with Stratasys' PolyJet or 3D Systems' MultiJet, the other is made up of highly conductive silver nanoparticles.
The DragonFly 2020 jets these two materials layer by layer, beginning with the underside conductive traces and ending with the topside conductors. The result is a functioning circuit board. Once all auxiliary electronics are added, such as transistors and resistors, users can begin testing their PCB concepts.
“We realized from the beginning that inkjetting was the key technology for this application,” Fried explained. “There are a few areas where we see the technology as being a strong one. The printers most capable of multimaterial 3D printing are inkjet 3D printers. In the future if we want to increase the speed and size of such a system, we can add more printheads.”Though similar to other inkjet 3D printing processes, the DragonFly 2020 3D printer and the inks, both developed by Nano Dimension, are designed specifically for the circuit board printing process. For instance, the photopolymer used for PCB printing is not the same material utilized by other inkjet 3D printers, Fried explained. The material is engineered to be a functional material, to have specific dielectric properties, necessary to insulate the conductive ink and allow for subsequent layers of circuit boards to be built. Additionally, the dielectric ink features high thermal stability and can even withstand temperatures up to 300 °C (572 °F).
Nano Dimension's AgCite brand of conductive ink has been developed with a license from the Hebrew University of Jerusalem through the Yissum Research Development Company. Made up of highly conductive silver nanoparticles, the material is engineered depending on the substrate on which it will be used, with the shape, size and distribution of the silver particles optimized for maximum conductivity.
While the dielectric ink is cured with a simple LED lamp, the conductive ink is sintered by an energy source, another clear distinction from traditional inkjet 3D printing. Fried indicated that this sintering process, built into the DragonFly 2020 3D printer, is a necessary step for fusing the particles into a solid conductive trace.
Also unique is the resolution possible with the DragonFly 2020. Depositing photopolymers at layers as fine as 2 microns, the printer is capable of finer resolutions than any other photopolymer jetting process on the market. This is a necessary requirement for the fabrication of PCBs being developed for new generations of electronic devices.
Changing the Printed Electronics Industry
With the DragonFly platform, Nano Dimension is bringing innovation both to the worlds of PCB production and 3D printing. In the present, 3D printing functional materials, such as conductive ink, means producing custom PCB boards on the fly. In the future, the technology lends itself to fabricating fully functional end parts.
Fried pointed out that, at just 3 mm, the Z-axis height of the DragonFly 2020 3D printer may not be all that impressive to those in the 3D printing industry, but it leaves plenty of room for printing complex multilayer boards.
“There may be about 16 layer boards in your smartphone. Those boards are expensive and take time to make. The more complex the board, the more layers there are and the greater the justification for bringing the technology in house. Although even lower layer counts will benefit from the speed of iteration” Fried said.
According to a recent survey of 300 electronics manufacturers and designers conducted by Nano Dimension, 93 percent of respondents turn to short-run third-party manufacturers for their PCB prototyping needs. All respondents spent at least $10,000 per year on prototyping their circuit boards, with 43 percent spending between $10,000 and $50,000 and some spending over $100,000 on prototyping PCBs annually.
Fried compared the power of Nano Dimension’s technology for PCB design to the abilities 3D printing offers mechanical and design engineers. “In one corner of the lab, you’ve got your mechanical engineer who is able to iterate designs quickly by 3D printing them one after the other. In the other corner, you've got the software engineer who can just test out the software as soon as it's created. Then, you've got the electrical engineer in the middle of the room wishing he or she could test out designs so quickly, but he or she may have to wait several weeks for the prototype to come back from a PCB supplier.”
“Another consideration is the IP,” Fried added. “How long do you want to sit with your IP in-house before you risk taking your designs to a third party to have your board manufactured?”
Fried explained that, at the moment, PCBs 3D printed with his company’s technology may not be as strong as those made with traditional manufacturing, but they open up new design possibilities. For instance, PCBs aren’t limited in the planar shape they currently use and can even have some free-from geometries and cavities, though, because Nano Dimension has not yet introduced a soluble support material, they may not have the overhangs and other geometric complexities associated with other 3D printing technologies.
In the same way that 3D printing has brought a tremendous change to manufacturing, Fried pointed out that the ability to design PCBs for 3D printing will open up new possibilities in circuit board production that not even Nano Dimension can envision quite yet. “We present the technology to labs, and at first, it seems like it may just be a machine for prototyping PCBs, but soon these researchers are thinking, ‘I wonder if you could do this with it,’ or ‘What if you tried using it for that?’ It seems like it may just be for prototyping circuit boards at the moment, but I think we’ll see some very interesting uses for the technology very soon,” Fried said.
Multimaterial 3D Printing
Fried explained that the holy grail for electronics printing is the ability to print with copper inks, due to its high conductivity and low cost. However, the material is difficult to work with in nanoparticle form as it oxidizes quickly when exposed to air and, oxidized, does not conduct electricity well. In turn, Nano Dimension began with silver inks simply because the material was furthest along for the purposes of 3D printing PCBs, but the company continues researching the development of copper materials and filed a patent for a proprietary copper ink in November 2015.
Until that copper ink is released, Nano Dimension is continuing work on other materials as well. For instance, the firm signed an agreement with Tel Aviv University related to nickel nanoparticles. Nickel has good mechanical and corrosion resistance properties, but nickel nanoparticles ink is complex and has to be carefully formulated for jettability.
As the university has developed a method to stabilize nickel nanoparticle suspensions, Nano Dimension’s technology could enable the embedding of nickel-based sensors directly within PCBs. This ability, not possible with traditional PCB manufacturing, would allow for the creation of circuit boards with the built-in capacity to monitor such energies as magnetism, radiation and temperature.
Nano Dimension’s technology is not limited to photopolymers and conductive inks. In a surprise move, the company announced this May the successful 3D printing of stem cell–derived tissues in conjunction with Accellta, another Israeli firm in the bioengineering market.
Fried spoke to the partnership: “We started to think about how most bioprinters use an extrusion-based technology, which makes them significantly slower. We thought that, as inkjetting is a much quicker process, we might be able to 3D print with cells at a faster pace. Those other systems also don’t always achieve the best cell viability. They will have maybe about 30 or 40 percent of the cells survive the printing process.”
Fried added, “So, we met a great partner and just performed some preliminary studies—just modified our hardware a bit and changed the inks to see what we could do. We were able to achieve 80 or 90 percent cell viability, which was just amazing.” Nano Dimension and Accellta are currently considering the launch of a join entity, a separate company that would not detract from the focus or funds of the founding firms.
The Future of Electronics 3D Printing
What these projects demonstrate is that inkjetting is highly extensible and not just suited to one material type. For this reason, printing conductive inks could feasibly be combined with printing a number of materials in order to enable additional electrical properties such as resistance, capacitance and inductance. In the near term, it might be possible to print flexible circuit boards using elastomeric photopolymer substrates, but, ultimately, this could lead to printing fully functional objects, according to Fried.
“Right now your smartphone consists of a PCB and a case, but it's possible to imagine the electronics all 3D printed together with the case,” Fried said. “Ultimately, with all of the components integrated into a single object, this could save space, allowing us to shrink the electronics even further.”
Though such a multimaterial electronics printer may not be rolled out this year, it is clearly something that Nano Dimension is working towards. It should be noted that it is not the only one. Other electronics printer manufacturers are working towards PCB printing capabilities, including Voxel8, Voltera, BotFactory and Chemcubed. Some of these solutions integrate features like machine vision and pick-and-place, allowing for the automatic assembly of circuit boards.
In Nano Dimension’s own backyard, there are a number of materials and inkjetting experts as well, including Stratasys, XJet and HP, all of which may have their own electronics printing technologies up their sleeves. HP, for instance, has already demonstrated the ability to 3D print strain sensors directly into nylon parts.
The competition may be steep for all of these players, but for the rest of us, it means that 3D printing is continuing to evolve. PCB printing today may mean 3D printing complete, fully functional objects tomorrow.