Home > SMT Assembly News

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:

  • Composition of lead-free cored solder wire for hand-soldering
  • Composition of solder bar for wave soldering
  • Composition of solder paste for reflow and hot air soldering
  • Composition of BGA Balls
  • Chemistry of flux to be used in lead-free soldering
  • Temperature resistance and tolerance of led-free compatible electronic components

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.


SMT Reflow Oven, Lead free Reflow Oven, Reflow Oven Manufacturer, LED reflow oven, PCB Reflow Oven, Nitrogen Reflow Oven, Dual Rail Reflow Oven, China Reflow Oven, wave soldering machine, Dual Rail Wave Soldering Machine, Nitrogen Wave Soldering Machine, Wave Soldering Machine Manufacturer.

Flason Electronic Co.,ltd provide a full SMT assembly line solutions, including SMT Reflow OvenWave Soldering MachinePick and Place MachineSMT Stencil PrinterSMT AOI SPI MachineSMT Reflow OvenSMT Peripheral EquipmentSMT Assembly lineSMT Spare Parts  etc any kind SMT machines you may need, please contact us for more information: wechat whatsapp:+8613691605420, Skype: flasonsmt, Email: sales@flason-smt.com
1) This is the first time I use this kind of machine, is it easy to operate?
There is English manual or guide video that show you how to use machine.
If you still have any question, please contact us by e-mail / skype/ phone /trademanager online service.
2) If machine have any problem after I receive it, how can I do ?
Free parts send to you in machine warranty period.
If the part is less than 0.5KG, we pay the postage.
If it exceeds 0.5KG, you need to pay the postage.
3) MOQ ?
1 set machine, mixed order is also welcomed.
4) How can I buy this machine from you? ( Very easy and flexible !)
A. Consult us about this product on line or by e-mail.
B. Negotiate and confirm the final price , shipping , payment methods and other terms.
C. Send you the proforma invoice and confirm your order.
D. Make the payment according to the method put on proforma invoice.
E. We prepare for your order in terms of the proforma invoice after confirming your full payment.
And 100% quality check before shipping.
F.Send your order by air or by sea.
5)Why choose us ?
A. Gold supplier on Alibaba !
B. Trade assurance to US$54,000 !
C. Best price & Best shipping & Best service !


Contact: Mr Tommy

Phone: +86 13691605420

Tel: +86 -755-85225569

Email: sales@flason-smt.com

Add: No.94,Guangtian Road,Songgang Street,Bao an District Shenzhen China