China
Africa
Explore chapters and articles related to this topic
Electronic Hardware Reliability
Published in Cary R. Spitzer, Uma Ferrell, Thomas Ferrell, Digital Avionics Handbook, 2017
P.V. Varde, Nikhil Vichare, Ping Zhao, Diganta Das, Michael G. Pecht
The IEC standard covers lead free issues for the management of lead-free termination finish and soldering of components and requires that the avionics manufacturers develop a control plan in accordance with IEC/PAS 62647-1 (GEIA-STD-0005-1). Most avionics applications are exempt from lead free requirements. As a response to the EU’s Restriction of Hazardous Substances (RoHS), the industry has predominantly settled on tin–silver–copper as the replacement for conventional tin–lead solder. To comply with RoHS, part manufacturers have sought lead-free finishes to replace the traditionally used tin–lead finishes. The finish selection is important in providing corrosion resistance, good solderability, and durable solder joints.
Contact Materials
Published in Milenko Braunovic, Valery V. Konchits, Nikolai K. Myshkin, Electrical Contacts, 2017
Milenko Braunovic, Valery V. Konchits, Nikolai K. Myshkin
The coating of aluminum or copper by different metals is one of the most common commercial practices used to improve the stability and suppress the galvanic corrosion of aluminum-to-copper connections. The most widely used coating materials are tin, silver, copper, cadmium, and nickel. Surprisingly, very few comparative studies have been published on the efficiency of these coatings in maintaining the uninterrupted operation of aluminum-to-copper connections under different service conditions. This is because the effects of coating materials are very difficult to separate from those associated with the connector design. Much of the available data are primarily empirical in nature.
The Analysis of Variance for Designed Experiments
Published in William M. Mendenhall, Terry L. Sincich, Statistics for Engineering and the Sciences, 2016
William M. Mendenhall, Terry L. Sincich
Evaluating lead-free solders. Traditionally, solders used in electronics assembly are made with lead. Due to numerous environmental hazards associated with lead solders (e.g., groundwater contamination and breathing in of fine lead-bearing particles), engineers are developing lead-free solders. In Soldering & Surface Mount Technology (Vol. 13, 2001), researchers compared the traditional tin-lead alloy solder to three lead-free alloys: tin-silver, tin-copper, and tin-silver-copper. A measure of plastic hardening (Nm/m2) was obtained for each solder type at each of six different temperatures. The data are given in the table.
Corrosion insight of iron and bismuth added Sn–1Ag–0.5Cu lead-free solder alloy
Published in Corrosion Engineering, Science and Technology, 2020
Nor Wahida Binti Subri, Masoud Sarraf, Bahman Nasiri-Tabrizi, Bakhtiar Ali, Mohd Faizul Mohd Sabri, Wan Jeffrey Basirun, Nazatul Liana Sukiman
The procedure for solder alloys preparation followed our previously described protocol [8]. In summary, the samples were prepared from pure metals (tin, silver, copper, iron, and bismuth) in the form of ingots. First, these pure elements were weighted in proper weight proportion. Then, to ensure proper melting, the pure metals were melted at over 1600°C for 40 min in an induction furnace. Subsequently, the melted metals were combined in a melting furnace with pure liquid tin at 290–300°C for 1 h. To provide an oxygen-free surrounding in the furnace and defend molten materials versus the oxidation, nitrogen gas was utilised. Thereupon, the molten alloys were cast in the form of disk formed ingots and a Spectrolab apparatus was employed to execute atomic emission spectrometry (AES) with nominally ppm accuracy to determine the exact compositions of the casting ingots complied with standard specifications per JIS-Z-3282:1999, as summarised in Table 2. After that, the melted solders were poured in the preheated moulds and were cooled to room temperature (about 25 °C). The as-prepared samples were disconnected from the moulds and inspected to verify that their surfaces were free of destructions and voids. Ultimately, the solidified specimens were held for 24 h at 25 °C to liberate some of the residual stresses caused by the casting process.