RoHS Compliance and Lead-Free PCBs
What is the significance of RoHS Compliance and Lead-Free PCBs?
Restriction of Hazardous Substances (RoHS) EU Directive has prohibited the use of 10 poisonous substances in electrical and electronic equipment. These substances are:
- Cadmium (Cd) (0.01% maximum)
- Lead (Pb) (0.1% maximum)
- Mercury (Hg) (0.1% maximum)
- Hexavalent chromium (Chromium 6) (0.1% maximum)
- Polybrominated Biphenyl (PBB) (0.1% maximum)
- Polybrominated Diphenyl ether (PBDE) (0.1% maximum)
- Bis(2-Ethylhexyl) Phthalate (DEHP) (0.1% maximum)
- Butyl Benzyl Phthalate (BBP) (0.1% maximum)
- Dibutyl phthalate (DBP) (0.1% maximum)
- Di-isobutyl phthalate (DIBP) (0.1% maximum)
Cadmium is restricted to 100 parts per million (0.01%) whereas the rest of the substances are limited to 1000 parts per million (0.1%). The above-mentioned maxim concentration of substances applies to each homogeneous material that the product is composed of. A homogeneous material is a material with uniform composition and cannot be separated mechanically into different parts.
The RoHS directive also referred to as lead-free directive was initiated to restrict the pollution of the environment by toxic electronic and electrical waste. The disposal of the products containing the above-mentioned elements even in small traces is harmful to the plants and animals present in the ecosystem. They pollute the surroundings and are also dangerous in terms of occupational exposure. RoHS is closely associated with the Waste Electronic Equipment Directive (WEEE). While RoHS controls the utilization of hazardous chemicals in electrical and electronic equipment, the WEEE monitors the disposal of these products. Nowadays in the PCB industry, even the laminates meet the ROHS compliance.
How does RoHS compliance affect my PCB designs?
In the past, the electronic industries used tin-lead solder to join the components since it provided the perfect bond. And also it was used as a surface finish to protect the copper from corrosion. Currently, tin-lead solder is no longer permitted
The lead-free solder requires materials with a high Td (decomposition temperature), as thermal profiles and dwell times increase.
What is Sierra Circuits’ solution for RoHS?
Since 2005, Sierra Circuits has been fabricating lead-free boards. Our lead-free boards are prepared with laminates that have a higher Td to bear the increased temperature and dwell times required during the assembly process. Additionally, we offer RoHS compliant surface finishes.
Lead-Free PCB Boards
We provide lead-free material like IS410 or R370HR and we use lead-free finishes like immersion white tin, immersion silver, immersion gold. If you are not sure about how to proceed, begin your custom quote or chat live with an account representative.
High-Rel Lead-Free PCB Boards
We, at Sierra Circuits, manufacture lead-free PCBs that can withstand up to 2000 thermal shocks from -45ºC to 145ºC. These special-purpose lead-free boards are created through our proprietary, patent-pending process. The quality and reliability of these lead-free circuit boards have been proven through meticulous HATS testing and our own solder float testing.
RoHS Frequently Asked Questions
If tin-leaded solder cannot be used, what other surface finishes does Sierra Circuits offer?
We offer the following RoHS compliant surface finishes:
- Lead-Free Immersion White Tin
- Immersion Silver
- Electroless-Nickel Immersion Gold (ENIG)
- Soft Bondable Gold
- Full Body Gold
Check out our surface finishes page for more information.
What changes will RoHS-approved PCBs bring, in regard to PCB laminates?
The laminate suppliers have developed resin systems compatible with the higher temperatures required for assembly. Our lead-free laminates are also UL approved. The laminate has a Td of 364 °C.
Can Sierra Circuits supply a Certificate of Compliance to the RoHS Directive?
Yes, as well as a letter of compliance from our laminate suppliers.
What is the best surface finish for RoHS compliant assembled PCBs?
All surface finishes Sierra offers are RoHS-compliant except for HASL, which contains lead. You can use ENIG, ENEPIG, OSP and immersion silver for your RoHS-compliant PCB. Check out our surface finish chart.
Do RoHS-compliant printed circuit boards take longer to process?
No. While there is an increase in the lamination process time, this does not affect the turn time.
How do I specify that the PCBs need to be RoHS compliant?
Add a note to your drawing, purchase order, or quote information (preferably all three) that states “Fabricate to meet EU RoHS Directive.” You can also request a certificate of compliance to the RoHS directive.
Will the RoHS-compliant PCBs have markings to identify them as lead-free?
Yes. The words lead-free or LF will be silkscreened on the board near the Sierra Circuits logo.