Soldering lead-free

Lead-Free Soldering and Environmental Compliance An Overview [Pg.2]

From the very beginning of the electronics industry (not to mention ancient solder appUca-tions dating hack 5,000 years), solder joints have been made primarily of alloys of tin (Sn) and lead (Pb). In particular, the eutectic tin-lead alloy (63%Sn and 37%Pb by weight, eutectic temperature 183 °C, or 361 °F) has been used almost exclusively in electronics, due to its unique characteristics (cost, availability, ease of use, and [Pg.2]

Solder interconnect reliability is the probability of the solder interconnects to perform the intended functions (electrical, mechanical and thermal), for a prescribed product life, under applicable use conditions (such as temperature, humidity, cyclic temperature variations, voltage, current density, static and dynamic mechanical loading, and corrosion), without failures. Failures may manifest themselves in different modes, such as electrochemical or mechanical, and may occur at various system interconnection locations (components, substrates, and/or solder joints). [Pg.3]

Over the last decade, the industry has studied a wide range of alloys to replace the tin-lead alloy. The alloy selection has been based on the following considerations (Ref 12-15) toxicity, physical properties (melting temperature, surface tension and wettability, thermal and electrical conductivity), mechaiucal properties, mi-crostructural characteristics, electrochemical properties (corrosion, oxidation and dross formation, and compatibility with no-clean fluxes), manufacturability, cost, and availability. Yet another important consideration for selecting the lead-free solder alloy for commercial use is whether or not the alloy may be covered by any patents. Lead-free alloy selection, as weU as associated patent issues, have been described in detail in toe literature in Ref 16-20. [Pg.3]

There are many solder alloys that do not contain lead, and various lead-free solder alloys will continue to be used in tbe industry. Currently, the industry (Ref 17) is converging on the ter- [Pg.3]

CA6 solder with 403 ppm lead UAh solder wiLli US ppm lead Mechanical L Md tree snider Qualilec lead free solder I (Jiruldefi lead liee sokJer 2 56% land snider 40% load solder 37% lead solder Wi anljmerry snider 4fe silver solder... [Pg.297]

Used with lead-free solder especially in card connector applications for mobile telephones, personal computers and smart media. .. [Pg.105]

Similarly, the various EU directives that mandate substance bans have initiated wide scale research and development of alternative materials. Lead is a case in point. Lead has been widely used in the electronic industry in solders. Lead-free solders have existed for many years but it was the mandate in the Restriction of use of certain Flazardous Substances Directive (RoHS) to have products free of lead by July 2006 that spurred industry research, planning and adoption of the substitutes. Annex I lists examples of Green Chemistry case studies where research was stimulated in response to legislation targeting hazardous materials. [Pg.10]

KEMI (2000). Non-toxic Environment. See www.kemi.se Aerojet Propulsion Division (1991) speaking at a conference on Alternatives to I ncinerable Waste Streams, California Richards, B (2002). Lead-free Soldering. National Physical Labs. See www.npl.co.uk/npl/ei/news/epparticle. html... [Pg.35]

An example of using the LCA approach for informed substitution is the DfE LCA for tin-lead and promising lead-free solder alternatives for electronics. The alternatives assessment was conducted at the request of the electronics industry, as it prepared for compliance with the European Union (EU) Restriction of Hazardous Substances Directive, which includes a phase-out of the use of lead in electronic products. With estimates of worldwide tin-lead solder use at over 176 million lb (80 million kg) per... [Pg.129]

Conventional tin/lead solders have the approximate composition Sn63/Pb37 by weight, corresponding to the eutectic mixture, which is close to SnsPb, with a melting point of 183 °C. Lead-free solders are often composed of tin with 3 % silver and 0.5-1% copper, and have a melting point of 215-220 °C. [Pg.3]

In spite of a tremendous amount of effort for the search of lead-free C4s, no industry standard has evolved as yet. Commonly cited lead-free solders are Sn-rich alloys for which electroplating processes are available. The most popular lead-free solder among them is Sn3.9AgO.6Cu with a melting temperature of 217°C. This solder is recommended by National Electronic Manufacturing Initiative (NEMI) and has been extensively studied and characterized by NIST. However, applicability of this solder as a C4 material in chips with advanced ILD is not known. [Pg.233]

Currently, there is no unique solution to lead-free C4 material that is available at this time. Based on the above discussions, it is anticipated that the selection of lead-free solder for C4s will be dictated by the interconnect materials in the chip and by the selected packaging solution. Therefore, the lead-free C4 material selection is expected to be application-specific. [Pg.233]

The lead-free solders are mostly based on Sn-containing binary and ternary alloys. Among them, the Sn-Ag system is one of the earliest commercially available lead-free solders and has been recommended for general-purpose use as a substitute for Sn-Pb eutectic solder. Addition of nano-particles of second phase helps in improving thermo-mechanical properties such as melting temperature, mechanical strength, mechanical fatigue resistance, creep resistance and solder-joint reliability. [Pg.242]

Joints between metals, including those in electronic components, have traditionally used SnPb solders. However, in the European Union, new environmental legislation aims to phase out this use of lead by 2006 or 2007 a move to lead-free solders is also being made in Japan and the US. Eutectic SnPb solder exhibits many desirable properties... [Pg.344]

SMT detergent 440-R (10%-12% for RA solder paste, 10% for RMA solder paste, 6%-12% for lead-free solder paste, and 10% for SMD adhesives and post-solder flux [rosin and OA] buildup)... [Pg.163]

NF260./Indium Corporation No-flow epoxy underfill designed for lead-free processes 28,000 (10 rpm) 6 mos/24 hours Lead-free solder profile 2,800... [Pg.235]

However, the thermoplastic compositions exposed to a lead-free solder that are used as insulators begin to fail. Loss of insulating ability, which generally occurs after failure, renders the thermoplastic composition unreliable for these types of applications. [Pg.194]

B. Liu. Lead free solder friendly thermoplastic blends and methods of manufacture thereof. US Patent 7 037 986, assigned to General Electric Company (Pittsfield, MA), May 2, 2006. [Pg.206]

K. J. Steffner. Lead-free soldering. Fligh-temperature polyamides. Kunststoffe, 95 195-198,2005. [Pg.421]

H. Black (2005) Chemistry Industry, issue 21, p. 22 - Lead-free solder . [Pg.383]

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