Lead-Free (Pb-Free) Solder and Composition

Lead-Free Solder: Solder with NO Lead (Pb). Lead-Free is taking rapid momentum around the world after the EU (European Union) Directives to wipe off lead (Poison) from electronic soldering considering its health and environmental effects

RoHS: Restriction of Hazardous Substances [ lead (Pb), mercury (Hg), cadmium (Cd), hexavalent chromium (CrVI), polybrominated biphenyls (PBB) and polybrominated diphenyl ethers (PBDE).]

WEEE: Waste from Electrical and Electronic Equipments.

Why Lead Free in Electronics

Many of the electronic companies and manufacturers around the globe were using Tin-Lead (Sn/Pb) solder for PCB assembly and rework. They also used No-Clean Liquid Flux and No-Clean Solder Paste. They did not bother to clean the PCB and the flux residue after assembly. These boards were later dumped into earth.

While lead is dangerous and harmful during the assembly process, dumping the board in soil was harmful to the environment. This ultimately lead to make lead-free PCB assembly mandatory.

Lead Free Solder

Lead Free Solder

Lead-Free Solder

Various Chemistry for alloy composition in lead-free solder was explored. Several things had to be kept in mind:

The best composition of solder as per the experts are:

  1. Lead Free Solder Wire – Sn96.5/Ag3.0/Cu0.5
  2. Lead-Free Solder Bar- Sn99.3/Cu0.7
  3. Lead-Free Solder Paste – Sn96.5/Ag3.0/Cu0.5

Flux – Flux used in lead-free soldering has to be more active to withstand the high temperature.

6 Responses to Lead-Free (Pb-Free) Solder and Composition

  1. […] wire includes no-clean, water-soluble and activated rosin fluxes in both leaded (Tin-Lead) and Lead-Free solder alloys.  Alpha manufacturers flux cored solder wires with the highest performance for hand […]

  2. […] manufactures wide range of lead-free solder bar of different metal composition suitable for wave and dip soldering. Composition includes […]

  3. […] melting point of leaded solder (solder wire with lead) is less than melting point of lead-free solder wire. Hence, a lead-free soldering station must be of higher wattage for fast heating and fast thermal […]

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