Issue link: https://iconnect007.uberflip.com/i/1207026
16 SMT007 MAGAZINE I FEBRUARY 2020 imum quantity. You may not have that big of an order, but if your production planning group says, "We're going to build 100 of these boards tomorrow," at midnight, you have the 3D printers start printing masks, and you have the 50 printed masks that you need to do 150 boards because you can use them over about five times, and now you can have them by the next morning. You saved eight weeks and all that inventory. Cost is going to drive that. With 3D-printed electronics, it's going to still be relegated to very simple circuits because 3D-printed resistors, in particular, are very sen- sitive to moisture. The capacitors and induc- tors are also very sensitive to moisture, and the precision with which you can print is still not up to the level of what you can get with the traditional approaches in most cases. There's always the one-off. Somebody can always give you an example of having a perfect 3D-printed circuit, but building it in volume is a different subject. _____________ Glass Substrates Holden: Chuck, when you talk about ceramic, would the glass panel also be in that same cat- egory? I say that because Atotech showed a machine for 610x610-millimeter pattern plating of two-micron geometries on glass. Bauer: Absolutely. They have been working on that for several years with Dr. Rao Tummala at Georgia Tech. They're part of that consortium. Rao has retired now, but the program and the center are still there, and Atotech is a big part of that. Holden: At Gentex, they helped us do a 1x1-meter panel of electronic glass that we had metallized with ITO. We had phenomenal yield, and I hate to say how many packages came out of those thousands and thousands of meter-by-meter panels. Bauer: That's going to be a fascinating area over time because if you talk to the semicon- 3D-printed circuitry—not necessarily making a circuit board, but 3D printing of interconnect circuitry, especially with the advances in print- ing resistors and capacitors for interconnects. Do you think that might have an effect? Bauer: I've been playing around with 3D print- ing for about six years now in general, but not specifically in electronics. It's going to have an impact, but in a while—maybe the next five or 10 years. I doubt it will happen faster because things don't get adopted that fast. If you've ever worked with polymer thick film, for example, you know that we can print resistors, induc- tors, capacitors, no question. But it's like bur- ied capacitance in a PCB: How many people are doing that anymore? It's very hard to control and design, and unless it saves a lot of money and is a game- changer, it's not going to make a difference. If you're using 3D printing to do prototyping or customized products for a specific applica- tion, that makes a lot of sense, even today. But when you go to volume, there are niches where it works. In PCB assembly, the biggest appli- cation of 3D printing in the electronics world- wide is making masks for connectors during conformal coating. Feinberg: One of the reasons I asked is because there seems to have been a tremendous advancement by the people at Nano Dimen- sion, and the number of machines that they're selling has gone up exponentially over the last six months. Also, the majority of what they sold seems to have been to the military. Bauer: And the reason for that is that the mil- itary has the most customized needs in the world. Feinberg: Right, and they also are less cost-sen- sitive. Bauer: Correct. It is amazing. As I said, the big- gest electronics application has been masks for connectors because if you order masks for con- nectors, you have to order them six or eight weeks ahead of time and must order a min-