Issue link: https://iconnect007.uberflip.com/i/1520956
14 PCB007 MAGAZINE I MAY 2024 LaRont: What about the pretreatment of material for the 3D printing process? at is an interesting area as well. Recently, we have seen more chemical suppliers with chem- istry that pretreats the material surface before you put down the ink. But what is most interesting is the prospect of using the inkjet as a coater, replacing the whole coating process with 3D printing tech- nology as an initial step, while continuing to use direct imaging lithography. e 3D printer will coat nicely and do a better job at managing thickness. It can replace one of the dirt- iest processes we have with a sustainable technology. If you use it as a coater, the qualification challenges go away. Matties: Another huge benefit on the fabricator side is they are getting rid of many process steps. e fabricators want it. It's the qualification approvals that are stopping it. is is the first logical step. If I were to make a mar- keting plan for this, I would first try to sell our 3D printing coater as a replacement for the existing coater, which doesn't need half the controls as the one that makes a pattern. at way, you can get the solder masks mass qual- ified. You can formulate the mask for blanket coating. e next step is pattern printing. You do it in two steps. Don't try to eat the elephant in one bite. Matties: I like that. Coat, image, and mask is the order of priority. Other than solder mask technology, are there other additive processes that you see developing? 3D printing is a big topic, but there is also addi- tive plating, which is talked about a lot. In that, they are trying to use very thin seed layers, or even trying to sputter-direct. ey start with bare laminate, or they etch off the copper and build it back up, making their own seed layers. Creating substrates through this process is the source of some of the largest yield challenges. ere are a whole host of different, leading- edge processes that are available for substrate build-up. Right now, I believe the truly leading edge is more on the dry side, outgas- sing the surface, kissing it with the plasma treat- ment, then putting down metals—copper or cop- per and titanium. It's a very controlled process. It's always cheaper to do wet process, and you still can with defense and aero- space. But with the high price and low risk toler- ance of military products, the dry process is a better choice. People are explor- ing this trade space. ere is a lot of push to develop both wet and dry, but as of today, I'd say the dry side is very slightly ahead. ere's a lot developed in both directions. Matties: What makes building up substrates so challenging? Just think about it compared to a regular cir- cuit board. Historically, with conventional cir- cuit board manufacturing, we just metallized bare dielectrics in the holes; whether it's a through-hole or microvia, it's a hole. e holes are an order of magnitude larger than the fea- ture sizes. Typically, on the leading-edge sub- strates, you will have to use full SAP and sim- ilar processes. As a result, people are learn- ing about the fluid dynamics of dealing with the whole surface of a circuit board. You end up with defects here and there. Whether the