3D Printing May Ease Semiconductor Shortage Woes
Additive manufacturing can't do much in the way of complex ICs, but it can replace legacy passives and improve existing fab machinery.
Of all the industries affected by the COVID-related supply chain issues, the electronics industry has arguably been hit hardest. For this reason, several companies have searched for solutions outside of conventional manufacturing to stop the bleeding.
3D printers can, in some cases, be used to create circuit boards. Image used courtesy of Voltera
But the move beyond traditional marketplaces has introduced a slew of problems for designers and companies alike. For one, many engineers have encountered a burgeoning "gray market" of counterfeit chips that have flooded the sites of unauthorized distributors.
On a larger scale, semiconductor manufacturers (like TSMC) and foundries have announced plans to combat the shortage by expanding production facilities. But this endeavor can cost between $10 to $15 billion for construction and can take years for the facility to be fully operable.
One way to side-step the shortage and the gray market altogether is through 3D printing, also known as additive manufacturing (AM). While 3D printing isn't an option for many complex ICs, this technique can do the job for certain components and even entire boards.
In fact, the ESA's WISA Woodsat scheduled for takeoff at the end of this year will include 3D-printed electrical circuits and 3D-printed electrically-conductive plastics to power onboard LEDs.
First polyether ether ketone ("PEEK") composite models printed for the ESA. Image used courtesy of Zortax
The Additive Manufacturing Process for Components
To develop simple passive components, several 3D printing techniques have proven effective, including:
- Fused deposition modeling (FDM)
- Polyjet printing
- Stereolithography (SLA)
- Photonic polymerization
Regardless of the specific method, AM for electronic components starts with a digital CAD model. This design serves as the instruction model for the printer, including all the required dimensions. 3D printing components usually involves copper-based thermoplastic filaments, but carbon- or graphene-based thermoplastic filaments can also be used.
Some companies like Voltera offer multi-functional circuit printers. Image used courtesy of Voltera
Once the printing process takes off, the part's trace is generated. These electronic traces are much wider and thicker than traces in other printing projects, however, to compensate for the highly resistant conductive ink, filament, or paint that make up the traces.
Using the requisite materials, the 3D printer can then begin adding layers to build a specific part.
What Components Can Be Feasibly 3D Printed?
One component that has been successfully 3D printed is the antenna. Antennae feature complex spatial material profiles and geometries that make it conducive for AM. Some researchers have proposed that 3D printing may bring about "the realization of microwave metamaterial antennas," specifically for 5G wireless networks.
3D printing allows for complex antenna geometries. Image used courtesy of AMFG and Optisys
The capacitor can also be successfully 3D printed. While traditional capacitors must be mounted onto a PCB, 3D-printed capacitors can be printed directly on the board. One company, Nano Dimensions, claims to already 3D print capacitors in a variety of dimensions with less than one percent component-to-component variance.
Other electronic components that can be 3D printed include inductors, sensors, interconnects, certain radio frequency components, and even entire PCBs.
Why 3D Print Components?
At the start of the pandemic, the AM industry stepped up to the task of producing essential parts for CT systems, protective gear, and ventilators. Now, the question remains whether this quick-turn manufacturing technique could remedy current chip supply shortages.
During the CoVent-19 Hackathon, makers and engineers innovated ventilator designs using 3D printers as needed. Image used courtesy of TCT Magazine
One of the benefits of 3D printing these components is that companies will not need to keep a bulk supply of certain passives. Instead, they might be 3D printed as needed. This would reduce dependence on the supply chain and make parts cheaper for the manufacturer, the engineer, and the consumer.
Another perk of 3D-printed electronic components is the space savings and customizability that they offer. While traditional components need to be mounted on a PCB, AM components can be printed directly onto the PCB. This would lend design engineers more flexibility to customize smaller form factors and enclosures.
Additive Manufacturing as a Supplement to Traditional Manufacturing
In a recent Forbes report, contributor Jim Vinoski argues that additive manufacturing can be used to ramp up efforts within traditional semiconductor fabs; 3D printing can enhance legacy machinery and production processes.
Speaking to Vinoski, Scott Green, Principal Solutions Leader at 3D Systems, explains that AM can improve a few key areas within a chip plant: wafer table thermal management and fluid/gas manifolds.
During chip lithography, the temperature of wafers must be strictly managed with cooling channels built into a wafer table. AM can quickly create uniform cooling channels to optimize the cooling process and reduce parts. Improving thermal management in this way can fine-tune equipment accuracy by one to two nanometers, according to Vinoski, which can speed up process time and boost wafer production.
This wafer table with cooling channels has been 3D printed. Image used courtesy of 3D Systems Corporation and Forbes
"With AM, it’s a digital manufacturing process that handles design changes immediately, and you can print single monolithic parts," Green explains.
Further, the traditional manufacturing process for fluid and gas manifolds is often plagued with vibration, leakage, erratic flow, and dead zones. Green says metal AM can ameliorate these issues by optimizing flow path, connection points, and structural components of process machinery. These 3D-printed improvements can, in effect, cut machinery parts and save weight.
The Challenges of AM Adoption Moving Forward
3D printing electronic components is not without its hangups, however. In an interview with TCT Magazine, VELO3D CEO Benny Buller explains that AM is best used for replacing existing parts—not redesigning a system altogether.
“When you are doing legacy parts that you are already producing in one way and just want an identical replacement by additive, the barrier for qualification is much lower," he said. "But when you start having to redesign the system or the assembly so that you can manufacture, well that’s not fine, because now you’re driving yourself into a lot of risk.”
Buller also notes that AM struggles to deliver the cleanliness and surface control one would find in the cleanroom of a traditional fab. At each layer of the semiconductor fabrication process, wafers are expected to be free of particles that are nanometers in size. This attention-to-detail cannot be replicated in an at-home or in-office 3D-printing environment.
Fab technician inside a semiconductor cleanroom. Image used courtesy of Forbes
Another long-term concern of additive manufacturing is the reality of illegal manufacturing. As 3D printers become more accessible, it will be difficult to prevent pirating of company IP.
Despite these challenges, it's possible that AM can be a short-term solution to long lead times on the semiconductor supply chain. Bringing AM to existing fabs can also meet the federal government's goal to strengthen semiconductor manufacturing on American soil.