Conductive Ink Printing for PCB Designers: What You Need To Know

When you’re a father, there are many things that you have to get really good at doing really quickly. While I could take some time in prototyping to work out all the kinks in my designs, I don’t have that luxury when trying to decipher why my kid is crying at 3 in the morning. As a result, I’ve developed some skill at making milk formula and changing diapers quickly.

If only I could’ve developed that sense of god-like speed in printed circuit board prototyping ten years ago when my clients expecting the printed circuit board (PCB) prototype to be manufactured within hours were left disappointed. Nowadays, with the emergence of conductive ink--not to be confused with carbon ink--for PCB printing, there have been substantial improvements in PCB prototyping. Instead of taking days or weeks, you can transform your PCB design into a functional prototype within hours or minutes.

What is Conductive Ink Printing for PCB Designers and How Does it Work?

Conductive ink for PCB design is basically a type of ink that contains an infusion of conductive materials like copper, silver or gold. Conductive ink printing allows PCBs to be created in an additive manner, with the dielectrics created before the layer of conductive ink is added on. This is very different from the conventional method of PCB manufacturing in which copper layers are etched away in a subtractive process.

Much like with solder paste application, the recent development of 3D printers had led to a new way to apply ink to form a conductive layer in PCB prototyping. While plastic material like ABS remains the most material used by 3D printers, various forms of material have been introduced to 3D printing, including conductive ink. This has lead to a handful of 3D printer companies developing specialized PCB prototyping 3D printers.

Flexible prototyping options with conductive ink printing.

The basics of conductive ink printing for a printed circuit involve a 3D printer that uses conductive and dielectric ink to create the desired circuit on a dielectric substrate based on the imported design files. Various manufacturers have striven to improve both the printers and the conductive ink, hoping to provide more prototyping options to hardware designers.

For example, a new type of conductive ink based on single-crystal nanoparticles allows printing on materials like fabric, plastic, and paper. Furthermore, 3D printer manufacturers are revolutionizing rapid PCB prototyping by introducing advanced features that were previously impossible, like printing multilayer PCBs.

Pros and Cons of Conductive Ink Printing

Conductive ink 3D printers offer an exciting prospect for rapid prototyping. You can turn your PCB layout into working prototypes within hours or minutes, depending on the size and complexity of the circuit.

Besides that, you’ll have the flexibility of shape and sizes when 3D printing with conductive ink. You’re no longer confined to symmetrical circuit board shapes during prototyping and can minimize overall cost. With conductive ink printing, you can print the circuits on various materials, like plastic sheets and paper. This opens up various possibilities for your design, especially in an age where smart wearables and IoT are emerging technologies.

Reduce your prototyping time from days to hours.

It may seem that conductive ink printing is the way to go with rapid prototyping. However, traditional PCB manufacturers are not likely to be phased out soon. Conductive ink printing involves certain drawbacks that hardware designers need to take note of.

For instance, commonly used conductive inks have higher resistance than copper tracks. You can expect economical conductive ink to have a resistance as high as 55 ohms per square, compared to only 0.5 milliOhms per square for copper traces. Of course, there are conductive inks with substantially lower resistance but they come at a higher cost. There is also a concern about the harmful chemical components of conductive inks, although research is being conducted to produce inks that are more earth-friendly.

Printing Your Own PCB From Scratch

Conductive ink printing for PCB designers in 3D applications is not fully-fledged as a comprehensive solution; in fact, most models are still in the developmental stage. However, the basics of 3D printing don’t shift much with conductive ink.

It requires a 3-dimensional data of your circuit board design before the prototype can be printed out. 3D printer manufacturers would normally be responsible for providing the software for converting 2D files into 3D formats. As for 2D files, they normally take the form of Gerber format, which can be easily generated by PCB design software like Altium Designer^®.

Have more questions on conductive ink printing with 3D printers? Talk to an expert at Altium Designer.