BANNOCKBURN, IL — IPC – Association Connecting Electronics Industries and its Solder Products Value Council (SPVC) have announced the release of a white paper summarizing phase two of a three-phase million-dollar research and testing program on tin/silver/copper (SAC) lead-free alloys.
In its ongoing efforts to reduce confusion regarding alloy choice and achieve a worldwide consensus on a standard alloy for the electronics industry, IPC's SPVC Lead Free technical subcommittee recently completed a down-select process of solder pastes and subsequent results of printed circuit board (PCB) assembly using lead-free alloys.
"The SPVC is moving forward to complete this very detailed reliability testing program, in what we hope will be an alloy that industry can use with confidence," says Peter Palmer, SPVC chair and vice president of global marketing at Cookson Electronics. He adds, "The final report will be issued in early 2005 and the entire project is a perfect example of what industry can achieve when we work together."
In order to preserve anonymity, six solder manufacturers submitted solder paste samples to IPC, which were forwarded to Engent (Norcross, GA) for testing. Tests performed included: reproducibility of printed paste volume, solder paste wetting and spread, interconnect voiding, and solder paste down select. As a result of the down-select process, one solder was chosen based on rank order of performance.
Two IPC-member companies, Flextronics and Solectron, volunteered to use the down-select solder pastes and a tin/lead control to produce lead-free test assemblies. Criteria used in the assembly process included: test and inspection, rework and repair, solder paste handling and storage, print operations, reflow process, and cleaning. Based on the statistical analysis of the assembly data, no significant difference in assembly performance was found between the lead-free solders.
The third and final phase of the program will include a summary of all tests completed to date as well as the results and analysis of long-term and thermal-shock reliability testing. The current 16-page white paper can be downloaded for free only by IPC members at www.ipc.org/MembersOnly or by clicking "IPC Members Only" at www.ipc.org.
