Gold, Silver, and Platinum: New Conductive Inks Offer Big Rewards in PCB Manufacturing

January 12, 2022 by Jake Hertz

Electroninks, a developer of particle-free conductive inks, is now adding gold and platinum inks to its portfolio. All About Circuits spoke with CEO Brett Walker to hear how this fabrication technology could extend Moore's law—and ameliorate the e-waste problem.

Conductive inks may drive the future of PCB manufacturing—at least when it comes to rapid prototyping. These inks, which often involve a combination of conductive materials like copper, silver, or gold, are gaining steam in fabrication because they can more easily accommodate the unique geometries and smaller enclosures of devices today.

Electroninks, a company that has been developing electronic ink solutions for almost a decade, made headlines today with the announcement of a new portfolio of ink solutions—including gold and platinum particle-free conductive inks.


Electroninks offers particle-free ink composed of metallic films with no binders.

Electroninks offers particle-free ink composed of metallic films with no binders.

All About Circuits had the chance to sit down with Brett Walker, CEO of Electroninks, to hear about the technology firsthand.


Electronic Inks for Fast Prototyping and Tight Enclosures

Engineers today are faced with the conundrum of designing smaller devices in complex geometries while also decreasing time to market. These pressing requirements have only compounded the need for more rapid design, prototyping, and development. Board-level manufacturers are researching ways to accommodate these needs without cutting corners on quality.

One solution that many have turned to is conductive inks: metal inks that can be directly printed onto substrates to additively manufacture PCBs. This means that manufacturers can create dielectrics before adding on the layer of conductive ink—a contrast to conventional PCB manufacturing methods that etch away copper layers in a subtractive process.

By using electronic inks, designers can instead print their circuits in tight and unique geometries directly in-house.


Example of package-level compartment EMI shielding using electronic inks

Example of package-level compartment EMI shielding using electronic inks. 


Walker explains that the premise behind Electroninks is to develop a mature PCB prototyping platform for the electronics community as a whole.

“Instead of needing to do these quick turn, rapid prototype processes, [Electroninks] allows you to have more of a desktop-style platform,” he says. “Once we reach full production volumes, it's very affordable for your average electrical engineer to make their processes far more streamlined.” 


A Straight Shot from Bitmap Outputs to Electroninks Printing

Electroninks offers a straightforward process from start to finish. Without requiring any special design or layout tools, an engineer can take existing bitmap outputs (from Altium or Autodesk's Eagle, for example), upload them to Electroninks’ software, and let an Electroninks printer do the work.

“The software on the back end is really streamlined,” Walker notes. “If you use Altium, great. Use Altium. If you use Autodesk, great. Use that. So long as you can export bitmap images and simple image files, those can be dragged and dropped directly into the platform. It prints it directly—no need to have a specialty design or layout.”

As a testament to this smooth end-to-end process, Electroninks has recently received a contract with the U.S. Airforce to help rapidly iterate and prototype PCBs for fighter jets, saving valuable time and protecting government proprietary secrets from threats in the supply chain. 


New Gold and Platinum Inks Expand the Portfolio 

Today, Electroninks announced the addition of gold and platinum particle-free conductive inks to its existing portfolio of conductive silver inks.

While traditional gold and platinum inks are based on metal nanoparticles dispersed with organics/polymers, Electroninks’ new offerings are particle-free. Instead, the new gold and platinum metal inks are composed of metal-organic precursors, materials that decompose cleanly and at lower temperatures than traditional nanoparticle inks. This material difference has large implications for mitigating e-waste

For example, on-chip EMI shielding—Electroninks' primary market—has traditionally required expensive stamped steel or stamped aluminum cans. With chemical vapor deposition (CVD) or physical vapor deposition (PVD), manufacturers must manage the vapor of metal in a controlled chamber environment. 


The effectiveness of EMI shielding versus the thickness of Electroninks coating

The effectiveness of EMI shielding versus the thickness of Electroninks coating. 

Electroninks says it uses 100 times less power than controlled or vacuum-style chambers. “It's significantly less power usage compared to plating baths—all this sort of wastewater that has toxic metals in it that you cannot release to the environment,” Walker says. “We are thermally curing an ink on the substrate. We don't use huge, highly-controlled water baths that you have to filter and do all sorts of post-treatment processes to.”

The inks are said to be catalytically active and have a high corrosion resistance, making them useful materials for protective circuits, gas, thermal, and biological sensors. 


Table comparing Electroninks offerings to nanoparticle-based alternatives

Table comparing Electroninks offerings to nanoparticle-based alternatives.

Electroninks says their gold and platinum inks will enable consumer electronics, medical devices, sensors, and semiconductors to be lighter, less expensive, and more environmentally friendly than previously possible.

“These new inks are important as they further differentiate our novel approach to conductive inks and further increase our material palette for applications in aerospace/defense, biomedical, and sensor applications,” Walker says. “This gives manufacturers a competitive alternative for high performance electronics instead of large plating baths or PVD deposition.”



All images used courtesy of Electroninks