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I spent time at IPC APEX EXPO 2015 talking about Isola’s launch of a low-loss, low-skew laminate prepreg with Fred Hickman, senior director of high-speed digital products. Hickman explains that the new material, Chronon, will be one of the enablers of 100 GB Ethernet applications.
Pete Starkey: Fred, it’s great to meet you. As the senior director of high-speed digital products at Isola, you are the ideal person to tell us about the new product launch. The brand is Chronon and it's a low-loss, low-skew laminate prepreg. Could you just give me a short introduction to this material?
Fred Hickman: Thanks for coming by, Pete, and thank you for giving me a chance to introduce you and your readers to Chronon. Chronon is indeed a new low-loss material for us. Essentially, it's one of the enablers, we think anyway, for 100 GB Ethernet applications, with a combination of good DK, 3.64 DK, less than .004 loss, but also excellent for skew. Fiber weave affects skew so it is a skew mitigator. So what we're proposing for people who currently use other competitive materials on the market, this is a drop-in material with very similar electrical, but very much improved skew mitigation capabilities.
So we have this product, Chronon, and last year we also introduced Tachyon 100G. Both have lower insertion loss, but Tachyon does not have the same ability to mitigate skew as Chronon.
Starkey: Are you in a position to give me a brief explanation as to how you've gone about minimizing the skew? What is it about normal materials that causes skew and how can that be overcome?
Hickman: With most materials, when you change the resin content it has a very big impact on the DK of the material. For instance, our best skew mitigator is GigaSync, changing the resin content from 50% all the way up to 75% and you get about a 3% change in the DK. So if you have lines going across resin/glass it doesn't matter because the DK basically stays the same. With Chronon, the DK change is only about 9% and in that same range, but with most other materials the DK range is around 20%.
Starkey: Oh, I see.
Hickman: So essentially what we're doing is using a combination of spread glass, also some proprietary engineering techniques with which we're minimizing the weave effect of glass.
Starkey: I understand now. It’s really on a microscopic scale. Because there's such a difference in product and concept between glass and resin, if you've got a material where the signal has a glass-rich area and a resin-rich area, you can sort of smooth that out while still keeping the benefits of woven glass reinforcement, but having that reinforcement much more uniformly distributed through the substrate.
Hickman: Absolutely. You hit it right on the head.
Starkey: Well, Fred. Thanks very much indeed.
Hickman: Thank you, Pete.