Reading time ( words)
We recently spoke to Ed Carignan of Technica, who outlines the current landscape for both direct imaging and inkjet printing and describes how the technologies have evolved over the years. He also details what’s next on the horizon.
Nolan Johnson: A lot seems to be happening for imaging. I would even go so far as to say that it seems that what’s now being called imaging is changing. How would you describe the landscape for imaging currently? How is it changing, and what’s on the horizon?
Ed Carignan: The biggest change that happened over the last decade was a large-scale conversion from standard phototool-based imaging to direct digital imaging (DI). The technology instantly allowed fabricators to improve registration accuracy, improve productivity, and reduce their reliance on individual operator skill. The change also benefitted PCB designers who could begin to reduce tolerance budgets for higher component densities. A variety of equipment manufacturers now populate this market, driving competitive pricing downward and made the adoption rate very widespread by both large and small PCB fabricators. The two significant contributors to the current success of DI were the development of the equipment platforms (laser-based, UV LED/DMDbased, etc.) and formulation changes made in dry film resist and solder mask materials to reduce photo speeds, allowing for fast exposure times.
What is new are inkjet-based systems used for the direct and additive placement of solder mask on the PCB panel. Inkjet systems for direct digital printing of legend inks have been available and in use by fabricators for many years. However, further improvements in platforms and print head technologies have made the potential for solder mask printing a reality. Similar to the DI development, this technology requires a careful match between the solder mask ink and the equipment’s ink delivery components. A key quality issue for PCB fabricators, assemblers and the end customer is that droplet placement by the piezoelectric, drop-on-demand print head engines negate unintentional placement of solder mask ink on solderable pads. With the development of print heads capable of jetting sub-6 picoliter droplet sizes, it is becoming viable to print solder mask inks directly in place of what was previously done in direct imaging and in an additive process, while also reducing the number of process steps in the bargain.
What will be exciting to watch is how much of that market will be transitioned to inkjet systems over the next decade as more equipment suppliers and more early-adopters ramp-up. There will likely always be a place where both direct imaging and inkjet systems co-exist for various PCB designs and constraints. At Technica, we represent solid partners in both technology spaces: CBT (Taiwan) for DI solutions and SUSS MicroTec (Netherlands) for inkjet equipment.
To read this entire interview, which appeared in the January 2021 issue of PCB007 Magazine, click here.