Electronics and electrical product industry is one of the main causes of environmental pollution. Thus, these industries are governed by several regulations imposed by governments in various countries. RoHS is one such compliance, which impacts the electrical and electronic industries. What is the compliance? How does it control the electronic industry? This post aims to answer everything you would like to know about these PCBs.
RoHS Guide: Questions on RoHS Answered
What is a RoHS Directive?
RoHS is an abbreviation for Restriction of Hazardous Substances. It is also known as Directive 2002/95/EC. This directive restricts the use of specific hazardous materials, which are used in electronic, as well as electrical products. RoHS directive originated in European Union. All electronics products in European market, since 2006 are required to meet this compliance.
Who Should Comply with RoHS Compliance?
Any business that deals with selling of electronic and electrical products, equipment, components, sub-assembly, and spare parts to RoHS countries should comply with this directive. Also, it is ideal for any business that sells to distributors, resellers, and integrators selling their electronics products to RoHS countries.
What is the Importance of RoHS Compliance?
The materials restricted under this compliance are found to have hazardous effects on the environment. They pollute landfills, and are known to adversely affect human health, if exposed to them for a long time.
What are the Substances Restricted under RoHS?
The following are the substances restricted under RoHS along with their specified maximum levels, if used:
- Lead (Pb): < 1000 ppm
- Cadmium (Cd): < 100 ppm
- Mercury (Hg): < 100 ppm
- Hexavalent Chromium (Cr VI): < 1000 ppm
- Polybrominated Diphenyl Ethers (PBDE): < 1000 ppm
- Polybrominated Biphenyls (PBB): < 1000 ppm
- Bis(2-Ethylhexyl) phthalate (DEHP): < 1000 ppm
- Benzyl butyl phthalate (BBP): < 1000 ppm
- Dibutyl phthalate (DBP): < 1000 ppm
- Diisobutyl phthalate (DIBP): < 1000 ppm
How does RoHS compliance affect PCBs?
Earlier, most electronic manufacturers used lead soldering to join various components. Also, the soldering was used as a surface finish to prevent copper from corrosion. Generally, the solder was heated before the process. Various studies suggest that workers exposed to these fumes developed severe health issues like asthma, skin defects, etc. Thus, RoHS prohibits the use of tin or lead in the soldering, and promotes the use of lead-free soldering.
Lead-free soldering has a specific requirement – it is only applicable to materials with a high Td (decomposition temperature).
What are the popular lead-free surface finishes used by PCB manufacturers?
The following are some common types of lead-free surface finishes offered by many PCB manufacturers:
- Lead-free Solder ( HASL)
- Electroless Nickel Immersion Gold ( ENIG)
- Lead-free Immersion White Tin
- Immersion Silver
- Soft Bondable Gold
- OSP ( Organic Solderability Preservatives)
- Immersion Tin
In the next installment of the post, we will discuss another set of questions on the RoHS compliance.