Issue link: https://iconnect007.uberflip.com/i/1330321
66 PCB007 MAGAZINE I JANUARY 2021 the product distortion would have been. It's fascinating that we can use so much computer horsepow- er to do something in a few sec- onds and on a very complex level. Holden: Is there some group or some company that particularly dominates that kind of software, or does everybody have to devel- op it on their own and go through the evolution of improving it? Carignan: They all seem to devel- op their own. In inkjet, there are all the same pressures, like cam- era acquisition of fiducials, linear and nonlinear distortions, and time to print. The inkjet people have to do exactly what di- rect imaging does, and they have to do it right out of the box because people become accus- tomed to going from CAM to the floor and then printing every side instantly within a second or two. The bar has been raised by the direct imaging market. No one is now going to step back with inkjet and say, "We're waiting while there's a bunch of processing." Holden: In 1980, we put together an inkjet leg- end system at HP using our thermal inkjet be- cause we wanted to serialize every single indi- vidual board with a unique serial number for traceability. That was always a nightmare un- til we came up with building our own big ink- jet printer and board handler. We got involved with changing the formulation of the white ink because we helped develop the inkjet heads, which are electroformed nickel. They repaid the favor by modifying some of the inks for us. The inks were not as good as solder mask or thermally-cured legend, but at least it got the job done. Carignan: It's there already. You can buy these inks from various companies. They've been formulated. The next evolution is getting rid of dry film resist. If you're going to be print- ing solder mask, which is a nice application, you'd want to do the same in inner layer print- ing and outer layer printing, but you see fewer people doing this. The next evolution is available today. Some people are using formulated systems for etch resist and plating resist. Picture yourself in a very small shop, where you have an inkjet printer, and say, "I'm going to be printing all inner layer resist additively. I don't need to have rolls of dry film, a developer, or a direct imaging unit. I just need to print directly the image that I want and then go to etching. I don't even need a resist stripper." They all use water and consume electricity. Some of them have HVAC utility costs. They just need this nice little unit that directly prints etch resist, prints a plating resist later in out- er layer, prints solder mask, and prints legend even later. That's where this market is going. In one unit or units, with multiple heads, you say, "Wow, I can use it for inner layer, outer layer, solder mask, and legend." You look at the number and square foot that you've elim- inated, and it's astonishing. You look at the costs to run a shop like that. There are very low overhead costs, and you have a lot less waste treatment costs, water cost, and utility cost. Some people are even printing carbon ink. That's another triple play where you can be printing carbon inks directly for the wearable electronics industry and other industries. It's much higher quality than that of direct imag- Inkjetted solder masked PCB. (SUSS MicroTec PIXDRO/Electra Polymers ELECTRAJET EMJ-110 ink.)