For those manufacturers exempt from RoHS and similar legislation, maneuvering through a lead-free world is as challenging as if the exemption didn’t exist at all.
For those navigating a business landscape that includes the Restriction of Hazardous Substances Directive (RoHS) and other lead-free regulations, being an exempt manufacturer may sound like a relief.
But for those companies whose product categories fall within the scope of the RoHS directive—which includes medical, military, industrial monitoring and control, automotive and telecommunications products—finding items such as tin-lead terminated parts in a lead-free world is just as much work.
“We’re publicly committed to using lead-free products, and we’re investigating lead-free products,” said Greg Henshall, Ph.D., global engineering services at Palo Alto, Calif.-based Hewlett-Packard (HP). “But some high-end products are still lead-based.”
During “Best Practices for Exempt Manufacturers in a Lead-Free World” on Thursday, April 3, during the 2008 IPC Printed Circuits Expo, APEX and the Designers Summit in Las Vegas, members from exempt manufacturers discussed how they balance reliability with availability.
“Risk management is the overriding factor in transitioning to lead-free for automotive customers,” explained Richard Parker, lead technologist for Troy, Mich.-based Delphi Corp., which supplies mobile electronics and transportation systems. “New programs have been more easily transitioned in.”
Parker explained that a vehicle’s harsh environment makes it tough on electronics. “Automotive reliability requirements are tough,” he said. “Product reliability requirements are too long, anywhere between three to 10 years.” Parker cited a narrower process window in soldering environments, warranty issues, component availability and lack of field data for harsh environment products as reasons for the slow conversion to lead-free.
“Someone has to pay,” he added. “There is a cost involved.”
At Rockwell Collins, similar challenges are at work. Dave Hillman, metallurgical engineer for the Cedar Rapids, Iowa-based communication and aviation electronics manufacturer, said issues such as significant use life play a major factor. “Those B-52s are still up in the air,” he said of the subsonic jet introduced in 1955. “For our products to have a 20- to 30-year use is not uncommon.”
Henshall explained that ball grid arrays present the largest challenge for HP, as lead-free components can’t necessarily withstand the high temperatures needed to sustain boards that can overheat. It’s a task, he said, that the information technology corporation is ready to meet. “HP plans to transition complex business products to lead-free,” Henshall said. “But there are challenges to be expected, such as service logistics and increased warranty costs.”
To meet its industry’s concerns head on, Hillman said, the AIA-AMC-GEIA Lead-Free Electronics in Aerospace Working Group was formed in 2004. Made up of the Aerospace Industries Association, Avionics Maintenance Conference and the Government Engineering and Information Technology Association, the group has about 90 attendees and 10 active task groups. The group works on those issues that are unique to aerospace and military, and are within control. “The group puts together a series of best-practice guidelines to support lead-free electronics,” Hillman explained.
The group, he said, concluded that lead-free soldering is possible, but noted that it must be “conducted in a measured, controlled and methodical manner.”
For Delphi, transitioning from lead to tin for the termination finish on components has begun and is slated to continue beyond 2015, unless legislation forces the switch sooner. Parker said his OEM component database must track the finish and processing temperature capability. “Error-proofing the entire flow is important,” he said.
In end, Parker said, you just can’t leave anything to chance, and the transition is not a simple matter. “Test everything,” he advised. “Don’t assume you can just switch solders.”
