Sustainability in the electronics world includes finding new raw materials for fabrication that aren’t toxic to the environment and being recyclable for continual reuse. Circuit board assembly requires solder, a material that melts to form a solid metal joint between the pins of electronic components and the metal landing pads on the board. Solder, however, has traditionally contained high levels of lead and other hazardous materials, making it unsafe for humans and the environment. Printed circuit boards can utilize green technology and lead-free solder to protect against these hazardous materials; this approach to sustainable electronic manufacturing is a more environmentally friendly option and complies with the restrictions on hazardous substances (RoHS) regulations mandated for electronics sold in Europe.
The Benefits of Sustainable Electronic Manufacturing
Many materials used in electronics manufacturing are considered toxic for human contact and the environment. These materials include solder, protective coatings, plastics, paints, and more. As electronics are discarded and recycled, these materials can find their way back into the environment and sometimes even harm those who come into direct contact with them during recycling operations. Many safety restrictions govern these hazardous materials, including RoHS, to protect the environment and those in close contact with device disposal.
In addition to restricting hazardous materials in electronics manufacturing, the RoHS directive has created new, safer replacement materials. In electronics manufacturing alone, RoHS has been responsible for propagating lead-free solders to replace traditional solders that contain unacceptable amounts of lead. These new lead-free solders have also necessitated developing new or refined manufacturing processes to use these new materials. These changes have substantially lowered the number of toxic materials returning to the environment during electronics recycling.
What is the RoHS Directive in PCB Assembly?
The RoHS directive covers all items with an electrical or electronic component unless expressly excluded and sold in the European Union. Even items manufactured in other countries must still meet the directive’s requirements. These items include household appliances, electronics, electric tools, telecommunications equipment, toys, and other devices. The directive drastically restricts the amount of the following ten substances used in manufacturing:
| RoHS Threshold Levels | |
|---|---|
| Material | Maximum Permissible (ppm) |
| Cadmium (Cd) | <100 |
| Lead (Pb) | <1000 |
| Mercury (Hg) | <1000 |
| Hexavalent Chromium [Cr(VI)] | <1000 |
| Polybrominated biphenyls (PBB) | <1000 |
| Polybrominated diphenyl ethers (PBDE) | <1000 |
| Bis(2-ethylhexyl) phthalate (DEHP) | <1000 |
| Benzyl butyl phthalate (BBP) | <1000 |
| Dibutyl phthalate (DBP) | <1000 |
| Diisobutyl phthalate (DIBP) | <1000 |
While many of these substances appear in various forms for manufacturing electronics, lead is the most prominent for PCB designers. RoHS-compliant circuit boards use lead-free solder, plating processes, and RoHS-compliant components to withstand the higher temperatures required by lead-free solder. An experienced PCB contract manufacturer that understands all of the RoHS requirements and working with lead-free assembly techniques is essential.
Your Contract Manufacturer Takes Sustainability to Heart
For PCBs, a RoHS-certified manufacturer understands your needs and has experience adapting designs to the challenges of lead-free processes. However, there is much more to PCB assembly under RoHS regulations than changing solder types. Your PCB CM must exhibit the following:
- Requirements of the RoHS regulations
- Materials and components from RoHS-compliant vendors
- PCB fabricators that are also RoHS-compliant
- Facilities with isolated lead-free assembly processes from standard processes
- Documented procedures that demonstrate lead-free manufacturing processes’ purity
At VSE, we understand sustainable electronic manufacturing and have successfully built lead-free circuit boards for our customers for years. Over time, the RoHS regulations have changed and updated to include new requirements, and we refined our processes to keep pace with them. We train our staff to handle RoHS-compliant materials, and our facilities are designed with clearly marked areas for lead-free manufacturing processes to ensure your project’s purity.
