AGFA: From Film to Inkjet Solder Mask

Estimated reading time: 12 minutes

Louwet: The biggest part is controlled by the printhead technology. Most of them use the same kind of piezo technology so the basis is the same. But sometimes you need some tweaking, some pepper and salt. That's something that we do together with the printer integrators. This is less straightforward for the lower volume legend ink market but for high-volume solder mask market we can adapt and adjust specifically for the printer integrator.

Goldman: You mentioned, and I find this interesting, that you really need to print only where you need to cover certain parts of the board. Do your customers recognize that? Do they like the idea that they don't have to put the solder mask ink over everything?

Louwet: Of course, our customers who are the PCB manufacturers like the idea. Because for them it's faster and they save a lot of material. The important step is to get the OEMs on board.

Goldman: Yes, I guess it is something that is spec’d in. But it's obvious that you don't need it everywhere. Wherever there's bare laminate, why would you need solder mask over that?

Louwet: That is right. Because it is a digital additive technology, you can choose to print down a very thin layer in some areas or you can have a full uniform printed board as shown in the photo.

Goldman: Everybody should be happy. You're working on getting this out into the field, but of course, sooner or later the industry is going to want even finer features. Is that controlled by you or is that controlled by the Inkjet printer?

Louwet: It's controlled by the inkjet head technology. You have printerheads now that even go to one picoliter, so very small droplet sizes.

Goldman: The smaller droplet size helps to determine the width of your feature.

Louwet: The smaller the droplet, the narrower the line is, and you build up the line by putting several droplets.

Goldman: After it's printed, then it must be cured, correct?

Louwet: Our Dipamat inks are all UV-curable. Depending on the ink and application, a post thermal treatment, typically 60 minutes at 150°C, may be required.

Goldman: It looks like a nice in-between green, not too shiny, not too matte. Hopefully it'll suit as many as possible without any adjustments?

Louwet: Probably in Japan it's too matte, and in Europe it's not matte enough. But you can play a little bit with the print strategy. Depending on how you put down the final layer, you can build in some matting, or you can make it glossier.

Goldman: AGFA is based in Belgium, correct?

Louwet: Yes. Our headquarters is in Belgium, near Antwerp. All our R&D, as well as production of the inkjet inks as well as the film, is there. However, for our film the majority of the market is in Asia, about 75%. China is the biggest market, followed by Korea, Taiwan, and Japan. Europe is somewhere in between, and the U.S. is the smallest market. We have our own AGFA sales organizations in those areas and recently we have started to hire and train the team to sell solder mask in the future.

Goldman: That's a big step. But you will be very successful with it.

Louwet: Yes, it's a big step but very achievable for us. There were some solder mask specialists at the booth two years ago, and we now have talked with them again and showed them this result. They were really astonished that we could achieve this in two years’ time!

Goldman: Is there a certain minimum thickness? Is that controlled by the droplet size?

Louwet: Not really. Basically, you print it in multi-pass printing, so it's not just one print. You can build the thickness with increasing number of passes. Typically, it's 20 micrometer in thickness but you can choose to go to 30, 35, or even thicker. It is digital and additive so you can control it.

Goldman: That could be a nice advantage, to be able to control the thickness on different parts of the board.

Louwet: That's true. Next to the inks for PCB, we also have the part on the printed electronics, based on two different technologies. One technology is based on conducting polymer. It's called Orgacon, like organic conductor. It’s something that we have developed for our own antistatic properties of the film. We have converted and optimized it to an ink that's screen-printable and can be used for transparent electrodes for capacitive touch applications. That's more or less the standard now in the industry. When you need a transparent conductor for capacitive touch, you use this ink.

Goldman: That's very interesting.

Louwet: Then another new development is based on our silver nanoparticle technology. From that we made screen printing inks, and inkjet inks, opening the digital track. You can also combine it with colors, and so it can print functionality into packaging. The screen printing inks have a very high conductivity. That allows you to print very fine lines. It’s exciting. In printed electronics, 85-90% is produced by screen printing. It’s the technology to use right now, but also the inkjet will come.

Goldman: The fun thing about the inkjet on printed electronics is that you don't have to stay two dimensional. You can start thinking three dimensional.

Louwet: Correct. Like Nano Dimension with their Dragonfly printer. I think it's the right vision for the future. But it's still early, of course.

Goldman: But even if you had bent something, you could still inkjet print the surfaces without too much adjustment to anything. Assuming those inkjets aren't just pointed in one direction. If they are movable, they could be pointed in other directions.

Louwet: Yes, aerosol printing is a technology that is already used for 3D parts. It's also based on nanoparticles. Inkjet also has the capability of printing on 3D objects, but also 2D printing followed by thermoforming is possible. 

Goldman: It’s great that you're working on some very interesting new technologies.

Louwet: Yes. We're going from the old analogue film technology, and we're moving to the digital technology. It's a phase that we have to go through, but it is very exciting to do.

Goldman: I wonder if the film business will actually completely disappear, or just continue to drop off.

Louwet: I don't think it will completely disappear. If you look at the number of processors or imagers that are being sold even today, film will be there for some time. We continue to stay focused on our core business and we're also still improving the quality, because customers are getting more and more demanding. To image features of 30 micrometers, the quality of the phototooling film has to be very good. We are continuously setting the bar higher for our production.

Goldman: There's no end in sight. That's why we all love this industry. It's always changing.

Louwet: If you look to the film business in AGFA, it has been growing in the past years as we pick up market share so for us it's not declining just yet. For the longer term we envision that the decline in analogue business will be compensated by the growth of the digital business.

Goldman: Good to hear. Thanks so much for your time, Frank. It’s been a pleasure talking with you.

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