Issue link: https://iconnect007.uberflip.com/i/848773
16 The PCB Design Magazine • July 2017 NEW CHALLENGES FACING MIL/AERO SEGMENT due diligence the companies in the mil/aero- space undertake, and it's absolutely needed. "What a lot of companies do that I've seen, that we've audited, it's almost criminal the lack of protections they have, relative to firewall, file security, data security, who they send files to, how they store stuff. It's absolutely needed," he stressed. Feedback System Is there a feedback system in place between the suppliers, fabricators, assemblers, and cus- tomers in the mil/aero segment? "From the Zentech side, 98% of everything we do is turnkey, build to print, complex assem- bly. We buy all the materials, we build it, we integrate it, we test it, we'll ESS [3] it and then ship it off. We're almost exclusively working with a design that somebody else has put to- gether. Sometimes it's ours, but 98% of the time it's somebody else's design," Turpin answered. For Freedom CAD, Miller said there's not much process deviation between the commer- cial and the mil/aerospace world, in that they work closely with the board fabricators. "So much of what we design today is impedance- controlled or specialty materials. When we start the design process, we go and at least work with either the OEM themselves, who are the con- duit to their fabricator, or with their fabricator to get a stack-up and make sure that it's manu- facturable from their perspective, and going to meet the impedance and current-carrying ca- pability or requirements that are defined in the statement of work," Miller explained. "From a process standpoint, we treat the process of de- sign the same, whether it's consumer or com- mercial product or a military product. We have pretty rigid processes for placement sign-off, critical routing sign-off, and then for final pack- age sign-offs. As we go down the process, we're trying to get as detailed a review from the cus- tomer as we can during the design process. And I know anybody that's in the design commu- nity understands 'as I can' as a statement be- cause you have companies that say they review it. And you get further down the design pipe and you've now got things connected, and they come back and say, 'Oh, by the way, we need to move this component to the top of the board. We've got to change this or that.' So, you think you have something that's been signed off and approved, but in reality, until the product ships, it's a moving target." Lead-free Issues Remain The electronics manufacturing industry may have transitioned to lead-free years ago, but the military and aerospace markets are exempted from RoHS due to reliability issues. Electron- ics assembly providers working in such markets face the difficulty of sourcing advanced compo- nents in non-RoHS-compliant configurations. According to Turpin, the leaded require- ments for technology have become a lot more difficult to design in for one part, and then have become a challenge because it's harder to get the parts, it's more expensive, and the lead times are different. "The military has tried to embrace some level of RoHS commercial-type products, but for the hardcore aerospace and space, it's leaded," he said. Miller agrees. "That makes sense, and you guys have to deal with re-dipping or re-balling components that aren't leaded to meet that re- quirement. We tend to try to follow what the cus- tomer wants to have happen, but we'll point out to them if we see a problem—something that' s going to impact manufacturability downstream." Matt Turpin, Zentech.