At Electronica in Munich last November, attendees had an opportunity to see up close and personally some interesting options for printed electronics, including both the much-anticipated inkjet digital 3D printing and the more established screen printing.
Both categories of printing fit into what MarketsandMarkets says will be a $12.10 billion printed electronics market by 2022.
Within both inkjet and screen printing for printed electronics, there are a variety of choices – including types of printer and substrates, to types of inks and ink formulations. Each of these printing methods involves depositing electrically functional inks onto a substrate, which creates an active or passive device, such as a printed circuit board, thin film transistor, antenna or resistor.
Both of these printing methods mimic conventional printing in slightly different ways – screen printing usually deposits one layer of material, while inkjet always applies the ink in multiple layers. Both offer choices of substrate that may include polymer, silicon, glass, silicon oxide, paper and more. And, both are considered suitable for many different manufacturing applications, and for electronics used in antennas, solar cells, OLED, RFID, sensors and more.
My company, Nano Dimension, has pioneered a digital 3D printed circuit board printer that allows for rapid on-site prototyping of functional printed circuit board prototypes and 3D circuitry with our inkjet DragonFly 2020 3D Printer. Technologies like this are getting us ever closer to the “factory in a box” concept as, in this case, we print both the conductive material and the structural material, which will enable the printing of fully functional electronic products in one system. There likely will come a day when a user might print customized working headphones or a smoke detector on a printer that, layer by layer, incorporates the functional electronics into the 3D structure in ways not previously possible.
The table below looks at digital printing and screen printing for printed electronics, and examines some of the positives and cautions for each. Which works best for your needs?
|INKJET DIGITAL PRINTING||SCREEN PRINTING|
- Conductive silver ink (nanoparticle)
- Conductive copper ink (nanoparticle)
- Other conductive inks (gold, nickel, etc.)
- Dielectric inks
- Conductive silver pastes
- Other conductive pastes
- Dielectric pastes
- Digital printing is most suitable for applications that require high resolution printing
- Provides increased conductivity over screen printing for superior functional performance
- Most cost-effective solution for prototyping and small batches, as it requires no masks or stencils, nor plating or etching
- By easily printing multilayers of highly conductive ink, it allows for creation of smaller elements with the same conductive results as larger elements, thereby enabling development of smaller, thinner and even light weight products for applications such as IoT
- Allows designers to easily try and quickly assess new designs, including conductors in more than one plane (3D printing of conductors)
- Easily print on many different substrates
- Lowers production costs by using less ink than screen printing, reducing process steps and material waste
- Reduces environmental impact
- Contactless printing
- Well established processes
- Well established market
- Small-particle inks required for inkjet printing are available from just a handful of vendors
- Digital printing market is not as established as the screen printing market. Therefore it may require talking with an ink expert for the optimal formulation for your application and inkjet device type
- Process wastes expensive ink
- Results are not as conductive as with digital printing
- As screen deteriorates before replacement, printing quality may suffer
The world of printed electronics is evolving very quickly, and when it comes to gaining the always critical competitive edge, having the right technology in place at the right time has never been more important.