Meeting Current and Future Requirements of the Automotive Industry

Estimated reading time: 9 minutes

Kinner: Sure. Historically, one of the hardest things has actually been doing repeatable condensation tests because the chambers are designed to maintain a standard, or whatever conditions you set them to. So if you set it to run at 40°C/93% RH and you try and trick it to create condensation, the machine is saying, "Whoa, something's not right here! We'll take out extra humidity.” Or, “I need to put more in to keep the conditions standard.” So really what the NPL and we have been focused on is developing a test method where we're changing the temperature of the substrate, so that the chamber conditions remain constant and we're creating a micro-climate on the circuit board itself.

A lot of the automotive guys have these tests as part of their performance specification. Depending on who did it, what chamber, and what day of the month it was or how the stars were aligned, maybe you'd pass maybe you wouldn't pass. So the NPL's goal is to create a more repeatable, standardized test method. For us it's been a great opportunity to understand what material challenges there are, and what creates a great result in condensation testing.

Starkey: Do you find in the automotive industry that they're looking for internationally accepted specifications? Or do the individual OEMs like to be in control and set their own in-house specs?

Kinner: I think a little bit of both, but more the latter. They mostly have their own specs and they're all kind of the same, but a little bit different. For us, if there was an international standard it would be great. I think having a standardized methodology, regardless of the pass-fail criteria, the standardized methodology is the important part so that we can all be certain if we put the material into a test, we're going to get a result that's A, representative of real life performance, and B, repeatable and reliable.

Starkey: Is there going to be some sort of agreed standard coming out of the work you've done with NPL?

Kinner: I think that's the goal. There's a lot of automotive Tier-one suppliers involved in that project, so I'm hoping that there will be a standardized test that everyone says, "Yes, that's what we're going to use." But like I say, establishing the methodology is a key part of the process. As long as that's the central part of the test, then I expect the OEMs and Tier 1 suppliers will tailor it to their own requirements—that's normal. For us, it's been a fantastic opportunity to see what makes a great coating in a condensing environment, and we've published quite a few papers jointly with NPL, and on our own, where the real advantages of two-component materials become clear. They have inherently better barrier properties, but also they've been formulated to be applied more thickly, and encapsulate devices better, to get better coverage, and obviously survive the thermal shock cycling requirements of the industry. It's been a really great process for us to really show that the technology is performing the way that we think it should.

Starkey: Is there anything else you think we ought to talk about while we're here?

Kinner: Yeah, we could talk about corrosion. Following on from the last point where we were talking about the improved barrier properties and the improved thickness and edge coverage, nearly every paper I've ever written, and nearly every paper I've ever seen about conformal coatings in corrosive environments, the conclusion basically is if the coating isn't there then it's not going to give any protection. So for us, it’s the ability to encapsulate leads and guarantee that we're getting good coverage of all the vulnerable parts.

The same is with the condensation, with salt spray, with corrosive gases; we're just seeing an entirely different world of protection much closer to what we can achieve from potting than we can from traditional thin conformal coatings. So it's an opportunity for you to improve the protection, but also there's a case where maybe conformal coating wasn't enough, but potting was overkill. So, having somewhere in the middle, that's an interesting space where people have the opportunity to reduce the weight, reduce the thermal insulation characteristics of their material, and reduce some of the stress on their assemblies.

Starkey: Once you've got the formulation, it's all about the interactive applications engineering.  Not just in the sense of “applications” in terms of putting coatings down, but “applications” in finding the right material for the right purpose.

Kinner: That's it, and kind of formulating, tailoring, and really understanding what people are trying to achieve so that you can give them something, they put it in the machine, and it just works, so there's not really too much effort required by the user to make it perfect.

Starkey: And again, as Electrolube, you have definitely this reputation of rather than just offering a standard product and saying, "That's it, take it or leave it." You can customize the product to make it suit the requirement.

Kinner: Certainly that is our aim and our ambition, and we get it right most of the time. Just one last thing, it's sort of out of sequence, but tin whisker mitigation is another issue related to the coverage. Conformal coating is the proven mitigation strategy for tin whiskers, and again the improved coverage, the improved thickness of the two component materials again have shown a big advantage in mitigating against tin whiskers, so it's ticking a lot of the right boxes.

Starkey: That's great. Phil, we could ramble on all day, but I think that it's been really, really interesting to talk to you, thanks very much.

Kinner: Likewise, Pete. Thank you.

Starkey: Have a good day. Thank you.

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