Additive manufacturing might not be ready for prime time, but it’s making inroads.
Sometimes I find myself walking around the shop floor asking, “Why do we have all this very expensive equipment? There must be a simpler, cheaper way to make a printed circuit board!” And yet, despite phenomenal technological strides, our industry still uses the same basic manufacturing processes since the earliest days of circuit board production: drill – image – plate – press – repeat – then route.
Observing so many different processes, simple logic might make you think printing conductive ink would have replaced plating processes long ago. Yet while printed electronics has advanced considerably, it is not ready for prime time for all applications.
(Full disclosure: I spent a half-dozen years earlier in my career in the paperboard and flexible packaging industry, experimenting with various types of inks printing on materials that included cardboard, kraft boxboard, film, foil, and coated and uncoated paper.) Web-to-web printing of conductive inks can accomplish much, but the circuit board industry still primarily requires producing in sheet (panel) form to deliver the parts customers require. Moreover, conductive inks provide rather limited current capacity.
The world of 3-D “printing” may offer an opportunity to shift from so many manufacturing processes to fewer – and possibly simpler – approaches. Several years ago, I witnessed college students building a toy car via 3-D, using conductive ink to create a basic circuit board on the car interior, which was powered by a battery-driven electric motor. Deploying 3-D printing to create the car body and then printing conductive ink to create the circuitry on the car body, they built the car and circuitry far more simply than traditional processes would have required. That was a very primitive example, however, compared with applications that require dense circuitry, or complex builds including sequential lamination for a complex multilayer, tight impedance control, etc. Advances in 3-D printing have been more than impressive, but while the ability to have vias formed on, say a 45° “horizontal” angle, rather than on the current direct 90° “vertical” angle, opens the mind to interesting design opportunities (and challenges), the constraints of consistency, current capacity and component placement remain.
While these two very different technologies cannot fully replace the printed circuit board today, they are nibbling away at the fringes. When any technology in any industry begins to make inroads, show promise and generate revenue at the expense of existing mainstream technologies, it must be considered either a passing phase, or a disruptive, paradigm-changing opportunity that should be closely followed.
Both printed electronics and 3-D printing have one major thing in common: They require a complete reset – a total mindset shift – regarding how a “circuit board” is envisioned.
In the case of printed electronics, engineers – design, application and manufacturing – must rethink both shape and process. Web-to-web printing fits best in high-volume applications requiring flexibility. (Think ribbon cables, flex circuitry and volume.) The challenge for many engineers is considering which applications are indeed high-volume and require flexibility. For other engineers, it’s thinking about the packaging that might go on a printed circuit and how to build up “layers,” as it were, to replicate a traditional circuit board. Remaining focused on the existing paradigm of traditional circuit board design and assembly techniques, however, may well be the reason printed electronics is not yet a larger segment of the industry. The mental leap to reengineer based on different attributes, materials and processes most certainly is needed to truly take advantage of a very different, new technology.
If engineering minds have not been able to wrap themselves around how to integrate printed electronics into mainstream electronic circuitry applications, or design to take advantage of the unique characteristics of printed electronics, imagine how long it will take for others to fully embrace and harness 3-D printing in the electronics industry.
If conceptualizing printed electronics is difficult, doing the same with 3-D printing will be exponentially more so. Printed electronics requires rethinking two-dimensional design concepts. 3-D printing, however, demands thinking and designing in three dimensions. That means breaking away from physical limitations ingrained with two-dimensional product design and instead imagining the “what if?” the lack of physical constraints enables. For instance: a structure where each layer can be designed and built with variable thicknesses; designing a product where the product itself is the circuitry; or, in the same process, assembling and fabricating a product in which components are truly embedded.
To truly replace the status quo, a disruptive technology requires users to break from current thought paradigms and embrace the scary edges of design, process and most of all, thinking. So far, such a shift to enable mainstream acceptance and application of printed electronics does not appear to have occurred. In the case of 3-D printing, mechanical engineers have embraced and successfully implemented it into many facets of the manufacturing shop floor. Now, hopefully, it’s the electronic engineers’ turn to harness that radical new technology.
With two potentially disruptive technologies nibbling away at the applications of traditional electronic circuits, maybe there will be enough free-thinking engineers and design visionaries who together will reimagine what is possible when these disruptive technologies finally emerge. •