Alloy verdict: 'no difference'.NORTHBROOK, IL -- Recent analysis of three lead-free alloys found no "statistically significant" difference in performance. The tin-silver-copper alloys underwent standard industry tests for melt characterization A rather long and fancy word for analyzing a system or process and measuring its "characteristics." For example, a Web characterization would yield the number of current sites on the Web, types of sites, annual growth, etc. , wetting balance response and solder solder (sŏd`ər), metal alloy used in the molten state as a metallic binder. The type of solder to be used is determined by the metals to be united. Soft solders are commonly composed of lead and tin and have low melting points. Hard solders (i. spread. Such tests are used to determine process parameters and demonstrate their ability to form inter-metallic bonds (connections) between the circuit board and components. A recently released white paper report summarizes results of the tests on the 96.5-3.0-0.5, 95.5-3.8-0.7 and 95.5-4.0-0.5 alloys. The alloys were picked because their main components--tin, copper and silver--represent the majority of "standard" replacements for leaded solders, said the report's authors. The 96.5-3.0-0.5 alloy is generally preferred by Japanese suppliers. Likewise, the 95.5-3.8-0.7 alloy is generally preferred by NEMI NEMI National Electronics Manufacturing Initiative NEMI National Environmental Methods Index members. "These tests were designed to determine if there are any significant differences in performance between the three lead-free alloys," said Dr. Greg Munie of Kester Solder, who edited the 19-page white paper. "Based on the statistical analysis of the data gathered from the tests, the difference between alloys is not statistically significant." The next phase of testing will be long-term interconnection in·ter·con·nect v. in·ter·con·nect·ed, in·ter·con·nect·ing, in·ter·con·nects v.intr. To be connected with each other: The two buildings interconnect. v.tr. reliability testing, including thermal shock Thermal shock in mechanical models Thermal shock is the name given to cracking as a result of rapid temperature change. Glass and ceramic objects are particularly vulnerable to this form of failure, due to their low toughness, low thermal conductivity, and high and thermal cycling of the three lead free alloys. In that stage, Flextronics and Solectron will assemble 40 test vehicles using each alloy and eutectic tin-lead as a control solder paste Solder paste (or solder cream) is a mix of small solder particles and flux. It is used extensively in the automated soldering processes wave soldering and reflow soldering. . The white paper is available at no charge at http://leadfree.ipc.org/Lead FreeWP006.asp. |
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