Designs for newer electronic devices carry more stringent requirements on form factor, which places further constraints on component footprints. In new IoT devices, 5G-capable mobile devices, and wearables, one can expect the required level of functionality to continue increasing as time goes on, which makes a cramped situation inside the packaging for these devices even worse.
For designers who want to develop low-volume, high-complexity electronic devices, additive manufacturing can alleviate some of these form and fit problems in a number of ways. No matter how you go about packing more components into a smaller space, using an additive manufacturing system to 3D print PCBs can free you from the constraints of planar rigid PCBs and accelerate the development of new products. Let’s explore in more detail additive manufacturing’s impact on the form, fit, and function of a PCB.
3D printing allows the fabrication of PCBs with unique shapes.
How Additive Manufacturing Impacts Form, Fit, and Function
Form Factor Freedom
Rigid PCBs are typically rectangular for a few reasons. A large number of rectangular boards can fit easily into a panel, which increases manufacturing throughput with low complexity boards. They can easily accept edge connectors and will nicely align in most automated assembly equipment.
However, panels for more complex board shapes leave behind a lot of wasted material once boards are cut from a panel, and the entire process for panelization and finishing a board requires a large number of assembly steps. A multilayer board with high layer count can require dozens of assembly steps, and the required steps only increase if a board’s shape is not rectangular.
Working with a 3D printing system allows a designer to easily create a board that is not constrained to a rectangular shape. The ability to print a complex board in a layer-by-layer fashion in a single printing run allows designers to create boards with nearly any shape.
The layer-by-layer process used in 3D inkjet printing is naturally adaptable to multilayer boards, which eliminates the excessive number of assembly steps required for rigid multilayer PCBs, speeding up and further enabling innovation. Printing the finished shape directly also eliminates unnecessary material waste during manufacturing.
This freedom to customize a PCB’s form factor with 3D printing also allows individual PCBs or multi-board systems to be created with complex shapes and even non-planar geometry. Multi-board systems with unique shapes can be customized to have a unique fit and can even be printed in parallel with the right additive manufacturing system. The ability to print an entire multi-board system in a single run also allows designers to quickly test and modify their designs without being constrained by traditional manufacturing processes.
Customized Component Fit
Packing more functionality into new mobile and IoT devices is a major challenge going forward into the future. 5G-capable smartphones, newer smart devices, and wearables are already challenging the design practices used in their predecessor products. Boards are expanding to fit the entire case, components require even tighter fits into small spaces, and some new components are being designed specifically to accommodate the reduced space in these devices.
Smart devices, like 5G-capable handsets, smart electronics, and data-centric sensor arrays, require processing units like MCUs, CPLDs, or FPGAs that must fit within a small package on a ball grid array (BGA). One solution to accommodate thinner packaging is to embed a BGA in a recess in the substrate and use an escape routing strategy through the inner layers of the board. This type of embedding is theoretically possible with rigid multilayer PCBs, but the time and costs involved in routing copper to the BGA and cutting out a recess through multiple layers make this solution impractical.
Using an additive manufacturing system allows you to create space for embedding components in a multilayer PCB. The layer-by-layer deposition process allows a cavity for an embedded component or a BGA for an active component to be placed in the substrate during printing. You can then solder the component to the printed conductor, just as you would with a rigid board. Contrast this with a rigid PCB, where a cavity has to be milled into a substrate. This allows your board to take a flatter profile so that it can fit snugly into thinner devices.
3D printing allows you to accommodate a BGA and other surface mounted components.
3D printing also allows fabrication of custom conductive components with unique functionality directly on a substrate. Some examples include conductive sensing elements, antennas with unique geometry, inductors or coils, and embedded capacitors. Depositing conductors from nanoparticle inks in a layer-by-layer inkjet printing process allows these elements to be placed on a planar or non-planar substrate as the substrate is printed. You won’t have to use successive plating, etching, and pressing steps to place these elements in a single-layer or multilayer PCB.
Some components, such as antennas, conductive sensing elements, and some coil designs, are easily tunable when embedded on a non-planar substrate. The layer-by-layer printing process allows these devices to be placed on the surface layer of or embedded inside a non-planar substrate, which expands the range of functionality for these devices. This is particularly important for 3D-printed capacitors as the substrate itself can function as the internal dielectric.
Regarding non-planar antennas, adopting a non-planar geometry allows the resonance frequencies of the antenna to be tuned in such a way that successive resonances are not related to each other by integer multiples. This flexibility in tuning may allow designers to select particular frequency bands for wireless communication without requiring the use of an antenna tuning switch, which requires its own power and processing. This frees up more space on the board for other components. Researchers have been experimenting with non-planar antenna designs using a number of fabrication methods for some time, and designers have a real impetus to adapt these antennas to a digital manufacturing 3D printing process for non-planar PCBs.
With additive manufacturing affecting form, fit, and function of 3D-printed electronics, designers can start thinking of new ways to pack ever more functionality into new devices. The award-winning DragonFly Pro additive manufacturing system gives designers the freedom to create 3D printed PCBs with nearly any shape they can imagine in less time and with competitive costs. Read a case study or contact us today to learn more about DragonFly Pro.