Introduction of JIS related to lead-free solder and soldering

Toward July 1, 2006, almost all major electric and electronic manufacturing companies have been finished their development on lead-free soldering in Japan. To support the promotion of practical use of lead-free solder, preparation of standards is effective. The outline of standards for lead-free solder under preparation in JIS, ISO and IEC is briefly reviewed. To coordinate among these standards is quite important to avoid double standards. The main solders to be included in these standards are Sn-Sb, Sn-Cu(-Ag), Sn-Ag-Cu, Sn-Ag-In-Bi, Sn-Zn and Sn-Bi(-Ag). The most popular alloy systems is Sn-Ag-Cu, in Japan Sn-3.0Ag-0.5Cu is a normally used solder. The ideal standards should have material specification and test methods for solder, flux and mixture of them. In Japan Solder Research Committee of Japan Welding Engineering Society (JWES) is corresponding to both ISO and IEC to enhance consistency among the standards related to lead-free solder. The JIS of test method for lead-free solders had been already published in 2003 as JIS Z 3198-Part 1 ∼Part 7. They include the measurement for melting temperature range, mechanical properties by a tensile test, wettability tests and joint strength tests. According to the test method specified in JIS Z 3198-1, Solder Research Committee of JWES determined the melting temperature range of all lead-free solders that will be adopted in JIS.