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When lead-free solder is used in wave soldering, a slightly modified solder pot may be desirable (e.g. titanium liners or impellers) to reduce maintenance cost due to increased tin-scavenging of high-tin solder. Lead-free solder is prohibited in critical applications, such as aerospace, military and medical projects, because joints are likely ...
Soldering copper pipes using a propane torch and a lead-free solder. Solder is a metallic material that is used to connect metal workpieces. The choice of specific solder alloys depends on their melting point, chemical reactivity, mechanical properties, toxicity, and other properties. Hence a wide range of solder alloys exist, and only major ...
Additionally, tin is a more corrosive metal, and can eventually lead to the failure of solder baths [clarification needed]. [36] Lead-free construction has also extended to components, pins, and connectors. Most of these pins used copper frames, and either lead, tin, gold or other finishes. Tin finishes are the most popular of lead-free finishes.
The solder grade used for leadworking is plumber's solder (80% lead / 20% tin). [i] Although this is thought of as a high melting point solder amongst lead-tin solders, the solidus is relatively constant for all of these solders and it is the liquidus which climbs from the eutectic point at Sn 63% / Pb 37%.
Tin will grow "whiskers" due to tension in the plated surface. Tin-lead or solder plating also grows whiskers, only reduced by reducing the percentage of tin. Reflow to melt solder or tin plate to relieve surface stress lowers whisker incidence. Another coating issue is tin pest, the transformation of tin to a powdery allotrope at low temperature.
The most common dip soldering operations use zinc-aluminum and tin-lead solders. Solder pot metal: cast iron or steel, electrically heated. Bath temperature: 220 to 260 °C (for binary tin-lead alloys) or 350 to 400 °C (for lead-free alloys) Solder composition: 60% Sn, 40% Pb or eutectic alloy.
Tin whiskers were noticed and documented in the vacuum tube era of electronics early in the 20th century in equipment that used pure, or almost pure, tin solder in their production. It was noticed that small metal hairs or tendrils grew between metal solder pads, causing short circuits. Metal whiskers form in the presence of compressive stress.
Solder paste is used in the manufacture of printed circuit boards to connect surface mount components to pads on the board. It is also possible to solder through-hole pin in paste components by printing solder paste in and over the holes. The sticky paste temporarily holds components in place; the board is then heated, melting the paste and ...