Insulectro and Isola recently shared a combined booth during PCB West 2017. Insulectro has distributed Isola materials for years, and the companies wanted to focus on Isola’s line-up of high-speed, low-loss material sets. Insulectro’s Chris Hunrath, VP of Technology, and Norm Berry, Director of Laminates and OEM Marketing, sat down with me to discuss the challenges facing signal integrity engineers today, and some of the Isola low-loss, low-Dk materials that can help with their signal integrity requirements. You might find Chris and Norm speaking to a group of PCB designers near you.
ANDY SHAUGHNESSY: I'm here at PCB West with Chris Hunrath and Norm Berry from Insulectro. Chris, why don't you start off by telling us a little bit about what you’re finding in the field when it comes to signal integrity.
CHRIS HUNRATH: One of the things that comes up with my customers a lot in the industry is signal performance. That boils down to a lot of different things, but signal loss and signal skew are two very important things. From a material standpoint, we have a lot of different offerings. What we try to do is help customers match the right product with their application. One of the things that was done many times to help mitigate skew, is to rotate the image on the panel, but that makes for very poor panel utilization or material utilization. Very popular right now are square glasses. Some of the square glasses have better performance than others for a lot of different reasons. A lot of that is design related, but there are ways to work around that as well.
SHAUGHNESSY: Are you focusing more on this from a single integrity standpoint? I know you've had the recent release, you talked about that.
NORM BERRY: As Chris mentioned, all the work has been done to mitigate differential pair skew, but there are so many other factors involved. Copper roughness certainly; we've been driving that down lower and lower and lower. Our primary offering now is a two-micron roughness, but it's going even farther south than that. Every time it gets smoother, obviously, signal loss improves substantially and measurably, so we continue to drive that down. We also work with other suppliers who have offerings that help mitigate the roughness in the copper, which improves the loss and it mitigates skew. We've done a lot of research and we do present it. We presented this a number of times to IPC Designers Councils and have been invited to speak in front of many design groups to help provide that information in an effort to mitigate the problems they're going have with their designs once they become real time and real life.
SHAUGHNESSY: Like the saying goes, if you don't have signal integrity problems now, you will.
BERRY: That's true. I saw that in print actually. Because of that, we've become an asset to many of our fabricators, where their sales and front-end engineering groups are working with designers, CMs, OEMs, and we've been invited many, many times this year to travel with them and present and support some of their offerings to designers who have this skew or loss issue.
SHAUGHNESSY: Now we see all these boutique and hybrid materials coming out. I know materials like PTFE are hard for the fabricator to work with, but they have really low loss.
HUNRATH: PTFE has been a good material for signal integrity, but mechanically it's not very good. It comes with a lot of baggage. As Norm mentioned, the trend to go to smoother coppers has its trade-offs too, because the adhesion is not the same. Our customers need to understand that. If there's a work-around or a way of making a mixed-material package to get what they need, but still also have the board manufacturable and have it built for assembly without any problems, you need to put all that together.
To read this entire article, which appeared in the October 2017 issue of The PCB Design Magazine, click here.