Martin Cotton Discusses Ventec’s New Book and Low-Loss Materials

Estimated reading time: 8 minutes

During DesignCon 2018, I sat down for an interview with Martin Cotton, director of OEM projects for Ventec. Martin was a PCB designer for years, so he has experience on both sides of the desk. We discussed Ventec’s reasons for coming to DesignCon, their expansion into low-loss materials, and Ventec’s new I-Connect007 book, The Printed Circuit Designer’s Guide to Thermal Management with Insulated Metal Substrates.

Andy Shaughnessy: Martin, you may be the director of OEM projects for Ventec, but you’re still a circuit board designer at heart.

Martin Cotton: Absolutely!

Shaughnessy: What brings you to DesignCon?

Cotton: Well, this is our fourth year, and our third year actually having a booth here. We've come to DesignCon because it is the initial pathway into any product. Here in the valley, this is the place where you want your next-generation product. It's pretty much a very fertile ground in these halls. We can keep our eyes and ears wide open here, and obviously our customer base is here, from an OEM perspective and a PCB manufacturing perspective. Both come to this particular exhibition, so we have to be here.

If you're working with these wonderful network people and various other telco products, you know all the candidates.  These guys want to find out what the latest materials are. By being here, we get a real good snapshot of what's being asked. What's coming? It's two to three years in advance. Some of the things we did two years ago, we're only just seeing the fruits of our labor.

We're often now looking at 2020 before we see any reality. That gestation period is important, because we learn about the industry, what the growing trends are, coming to the seminars, etc., is good. It's really important that we're at a show like this, because even the connector guys are here and we learn about the connectors. We learn about simulation and what these people are doing on the simulation. We spend some time going around at the exhibition ourselves and it's important that that kind of learning journey, if you like, is passed over to us. That's a key reason. Being at DesignCon is as up front as you can possibly be to the future.

Shaughnessy: What's new for Ventec in 2018?

Cotton: What we're doing here principally is showing our very wide portfolio of materials, ranging from the normal sort of FR-4 types of material, all the way to thermal materials. Both from an IMS perspective, metal clad, etc. and also thermally conductive prepreg, such as VT-5A2, which is one of our latest award winning creations. It has a polymer matrix structure that offers broad compatibility with a wide range of epoxies or polyimides, including low-signal-loss materials, yet provides up to eight-times better thermal impedance than FR-4.

With IMS, we are becoming a world leader in this particular area of materials. It's like, we can't actually produce enough of it quick enough. It's really going strong. It's immensely powerful what's going on in the digital world. Just look at the automotive world with hybrid cars and e-vehicles, LED lamps everywhere. The thermal issue is key here. We're presenting our high-speed, low-loss materials as well as our tec-thermal range here. As frequency goes up more heat is generated, even in digital. You see these guys making these fantastic high-speed products, and you listen to the OEMs talking about 56 gigabytes and 112 gigabytes, the next generation, etc., that's heat as well. It's not just bits of information, there's a lot of heat bouncing around there.

The combination of having thermal prepregs with low-loss materials is very important. We build specific hybrids for people. That's an area we think where there is great potential and opportunity. We get great feedback from our customer base with what's going on and I think we've got it absolutely right. Designers ask me, "What is your low-loss material?" I tell them about tec-speed 10. Yes, we have other low-loss materials too, but tec-speed 10 really stands out with a Dk of 2.7, and a Df of 0.045.

Now some people might look at that and think, "It's only got a Df of 0.045. That's not fast enough.” Well, actually, it's well fast enough and in fact, our insertion loss numbers are world leading for that type of material. The Dk is what's really helping us here.  And with Dk change, we can look at the geometry. The whole point of low Dk materials is that you can bring traces closer to the reference plane or other layers, and maintain the track width, which means you don't reduce the track side. You don't increase the trace resistance. You don't increase the power required for the circuit.

It's got a whole design base. As you mentioned, I'm a PCB designer. Df is an energy release mechanism, and it's all about how fast you can release the energy. The Dk, for example, is all about how much energy you can store. So you can store less energy, you don't need to get rid of it so fast. That's the kind of core element to that kind of material, but to be able to change the geometry, we look at the whole structure slightly differently.

Now, we have other materials like tec-speed 20, which is ideal for automotive and radar applications, low-loss requirements. Our tec-speed 6 is another great low-loss material. Ventec is becoming increasingly known for its low-loss materials. We’ve always been known for polyimides, which we are world leaders at, and IMS certainly. But, certainly this kind of application where we're looking at real advanced types of concepts is something that we're very proud of. We work very hard to ensure that we deliver reliable materials to our customers, both OEM and PCB manufacturers. So by being here we can talk directly with the OEMs, we can talk with the connector guys, we can talk to all sorts of people all in this same room, which is what makes it unique and why it's the place to be.

Shaughnessy: DesignCon does well even during the downturns.

Cotton: I first came here probably 20 years ago. We had little booths here in the old days. It's grown beautifully. You look at the show now and it's like, “Ahh, this is fantastic.” DesignCon is something we really appreciate being at because we get a lot of instant feedback. We know exactly what's going on. We were out collecting some bit error rates this morning, from a guy yesterday who said, “I need a material for XYZ, etc., and I need a bit error rate of this.” At DesignCon, you can immediately clarify the reality and provide proof.

Shaughnessy: You mentioned thermal, and, not coincidentally, you all have a new book on thermal.

Cotton: Yes, The Printed Circuit Designer’s Guide to Thermal Management with Insulated Metal Substrates is authored by two colleagues, Didier Mauve, and Ian Mayoh. Didier is a world expert on thermal. Thermal is a growing industry. It's not just LED, it's not just automotive, base station applications; we're looking at all sorts of radar applications too. And you've also got the digital world, as I mentioned earlier, that is getting faster and thermal is going to be more and more important. You start looking at some of the environments these products are put in. There's not an awful lot of space to extract heat, so you have to consider some mechanisms. One of the things you're looking at, something that's already there, is the laminate.

So why not make the laminate thermally conductive as well. It's going to be there anyway, carrying tracks, carrying components, so why not get that to do some of the work. It's a bit like Formula One cars: They used to have the engine strapped on the back of an old frame, but now it's an integral part of the overall chassis. The engine is part of the dynamics of the car as much as the power source. And it’s the same with thermal material. If you make them part of the system, as a part of the design, you get double bang. It makes a lot of sense.

One material mentioned already which we are very excited about is our VT-5A2, which is a prepreg. You can make cores from it as well, but VT-5A2 runs 3.4 watts-per-meter-Kelvin in x, y, which is ten times the thermal conductivity of FR-4. You can imagine if you can put that into a regular sort of design, you now have got that thermal capability in a prepreg, which is processable in a FR-4 line. There's a lot of opportunity and progress there and it's an exciting area to be in.

Shaughnessy: Yes, you have a really good group of people. It was great working with you on the book.

Cotton: I appreciate that. In our OEM work we are so far out in front sometimes and are eager and willing to learn everything, that's the key. And that's our job: to learn, pass information through, and get better products that fulfil the requirements of today’s and tomorrow’s products. Our quality is excellent, our manufacturing is AS9100D certified, we have IPC-4101 Qualified Products Listing (QPL) for our VT-90H and VT-901 products, and we fully control our global supply chain, which gives us a clear competitive advantage.

Shaughnessy: Well, it’s been great talking with you, Martin. I appreciate it.

Cotton: Thank you, Andy. Good to see you.

Visit I-007eBooks to download your copy of Ventec International’s micro eBook today: The Printed Circuit Designer's Guide to Thermal Management with Insulated Metal Substrates