For companies making the transition to lead-free manufacturing, an
operational audit is invaluable.
New laws and regulations, as well as a change in supplies, have facilitated a transition to lead-free manufacturing in the EMS and OEM industry. Even with increased calls from customers regarding PB-free products, the way to know if you’re truly in compliance is by undergoing a thorough auditing process.
As an industry leader in all phases of OEM and EMS operation, IPC was ahead of the curve in implementing an auditing plan. The IPC RoHS Lead Free Electronics Assembly Process was the result of numerous meetings with representatives from IPC member companies. Its objective is to ensure that EMS and OEMs have the necessary tools and capabilities to audit their operations for lead-free compliance and stay that way.
However, even before IPC’s auditing process went into effect, government regulations and customer demand for lead-free products were leading some companies to audit their operations to facilitate the transition to lead-free operations.
Auditor Leo Lambert, vice president and technical director of EPTAC Corp., an electronics manufacturing training company in Manchester, N.H., says, “Many of the OEMs and EMS houses were driven by their customers to start changing. Those who started early were ready, and it’s evident today that many commodity types of products are lead-free.”
Still, questions abounded about how to compile a comprehensive auditing process. Greg Munie, conference director for IPC Printed Circuits Expo®, APEX® and the Designers Summit, was chairman of the blue ribbon committee for the IPC RoHS certification program when it convened two years ago. “All these different companies had input for a lead-free transition, so we compiled a detailed list of questions for them to answer as sort of a checklist,” he explains.
Lambert concurred. “There must have been 300 to 400 questions on the initial questionnaire and of those some were repeated in each section, making them redundant to the applicant,” he says. “But this redundancy made it easier to create a process to find out how manufacturers would be able to successfully make the transition to lead-free operation.”
Michael McCallion, lean manufacturing and best practices director of CTS Corporation, a global EMS based in Moorpark, Calif., says that the company began the auditing process before IPC developed its lead-free certification, and that what IPC released was very similar to what CTS used. “We were auditing using methodologies from our company’s ISO 9000/2000 process and we carried out external testing to the iNEMI guidelines,” he says.
McCallion says that, for a global EMS like CTS, having comparable data and a uniform auditing process made the process faster at all of the company’s plants. “As it stands, the IPC guidelines are recognized by the industry, customers and suppliers and achieving the IPC Certification bring credibility” McCallion says. “As all of our plants have the ability to run lead free, an internal auditing and test process allows for benchmarking within the corporation.”
An integral part of the auditing process is to ensure the entire supply line goes lead-free. Testing the integrity of the supply line is one of the biggest hurdles to maintaining lead-free compliance. “As you’re buying material, you’re pushing your suppliers to provide material declaration sheets that ensure what you’re getting from them are truly lead free,” Lambert says.
John Della Croce, president of Della Systems, an electronic contract manufacturing company in Ronkonkoma, N.Y., that is IPC RoHS and lead-free process certified, echoes Lambert’s sentiments about double-checking the supply chain. “When you’re making the transition [to lead-free manufacturing], you have to make sure that everything is inspected, and that lead and lead-free materials are segregated. All it takes is one part that contains lead, and you’re going to have problems.”
Another obstacle toward getting manufacturers to go lead-free is convincing more resistant plants to change. Following the lead of the European Union and China, Korea implemented guidelines for lead-free operation last year. California has detailed RoHS and lead-free directives. Still, there are some plants still playing catch-up.
Lambert says that’s no longer an excuse. “The directives from the EU were pretty well defined,” he says. “[They] were published early enough to allow all electronic manufacturers the time to review their products and processes, and make the appropriate changes.” One theory Lambert has is that some manufacturers were hesitant to switch because of reliability issues regarding lead-free solders and boards being used on exempted products.
“Lead-free solders melt at higher temperatures, and there are a lot of component leads on PC boards that are plated in tin,” Lambert says. “There are concerns about tin whiskers forming from the exposed high tin content on the board and in the solder joints. The addition of lead to the tin solders reduces the total overall percentage of tin in the allow and thereby reduces the chances of tin whiskers from forming and with the process going lead-free the concerns of tin whiskers are definitely highlighted and warranted.”
Cost also is a factor. For Della Croce, there is a substantial cost in training personnel including new equipment dedicated to the process. “In addition to controlling and segregating of the no lead and leaded material,” he says, “everything needs to be identified with new part numbers and labeled accordingly.”
The XRF, an X-ray machine used to detect the presence of lead, is a vital instrument for McCallion, who estimates that CTS spent around $250,000 on testing equipment. “We have a stationary and handheld version that we use to inspect all incoming and outgoing material, and for roving audits within the plant,” he explains. McCallion also says CTS purchased a wave soldering machines with titanium pots capable of withstanding the higher temperatures, rework and inspection equipment stations and hand soldering irons that are clearly identified as lead free only use.
There is a stationary and handheld version that is used to inspect all incoming and outgoing material, and for roving audits within the plant. Internal training for appropriate staff is also recommended, including but not exclusive to engineers, inspectors, operators.
Having a solid auditing program in place also can put a company ahead of the curve when the EU revisits its RoHS directive this year to determine if any additions to its initial list of RoHS are needed. However, Lambert notes the IPC program “is a lead-free audit, and we are not looking to make this document into anything more than checking for lead in the electronic manufacturing process.”
Companies that have been certified lead-free
- Axiom
- CTS
- C-Vision
- Della Systems Inc.
- DSC – Intrusion Security Products
- Matric
- Paramit
- ProWorks
- Raven Industries
- Riverside Electronics
- Solectron Charlotte
For more information on IPC's Certification for RoHS Lead Free Electronics Assembly Process Capability Program, visit www.ipc.org/LFCert.
