Issue link: https://iconnect007.uberflip.com/i/1116895
44 PCB007 MAGAZINE I MAY 2019 of nonwoven paper. We make similar products to that today, such as our Nomex® brand of papers that have very good temperature sta- bility and are nonflammable. They are used in a lot of different applications, so the tech- nology is out there to make it. The issue with THERMOUNT® when it was first made was it was designed for CTE control, so it had a good CTE, but the electrical properties were just okay. And again, THERMOUNT® was dis- continued well over a decade ago. Something like THERMOUNT® as a reinforcement is defi- nitely of interest because if we could make a reinforcement that has properties closer to the resin system, that would mitigate the major- ity if not all of the skew issue. There are some thoughts about whether a modern version of THERMOUNT® would have its place in the market. Holden: But what about the use of a non-rein- forced material that was a dielectric with or without being photosensitive since we can la- ser drill that? Andresakis: Those types of material are nor- mally used in chip packaging. We have a prod- uct here called Cyclotene™, and it has very high TG, very low CTE, and very good dielec- tric constant and very low loss. But it's a spun- on dielectric and is available as both photo- definable and non-photo-definable, but they're typically very thin layers. Again, they're most- ly for redistribution layers on chip packaging or semiconductor wafer-level packaging. The only thing I could say that's similar is Mitsui was making a product for a while they called Multifoil®. It was a resin-coated copper, so there was no reinforcement whatsoever, and it was used to make cellphones as well as some chip packages. The problem is you still have to start with some structural integrity in the package, so you have to be careful about how you do that. Holden: You mentioned the iPhone X, but that brings up SLP, which is kind of a new area be- tween chip packaging and traditional HDI that is thin. Andresakis: If you're looking at just dielectrics for consumer products and the really thin stuff, there's a place for certain materials there. But at some point, you need someplace to start. So, you may start with a core and just build up from there using these type of materials. Holden: By the same token, my forward theo- ry is regarding Ajinomoto film. Do you have a product in that space? Andresakis: Right now, the products we offer in that space are the liquid version. Ajinomoto has enjoyed a majority of the market share in that space for a while, and others are looking at developing similar materials. They're not rest- ing on their laurels, though. They are working on new and improved versions. Holden: What do you think of the possibility of graphene as a dielectric? Andresakis: I think of graphene as being used more in the conductor space. It typically has very good thermal and electrical conductivi- ties. Holden: One of the universities reported gra- phene that serves a conductor as good as cop- per and an insulator as good as Teflon. The same material can have two totally different states. Andresakis: Yes, modifications could be done to graphene to change its conductivity. Weldon: It will be some time, which isn't sur- prising. There's carbon that makes diamonds, There are some thoughts about whether a modern version of THERMOUNT® would have its place in the market.