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One of the universal issues that cause increasing concern is the environmental protection issues of electronic products. In the past few years, there has been a boom in digitization, global output of electrical and electronic equipment is exploding. Robots, drones, 3D printers, the Internet of Things (IoT), smart home assistants, and home medical equipment are all governed by RoHS, which are high relative to PCB producers and manufacturers.

Since July 1, 2006, the RoHs standard has been formally implemented, many great PCB manufactures follow this standard. PCBgogo is one of them who actively respond to RoHS standard.

RoHS is largely used to define the material and process standards of electronic and electrical goods in order to make them more favorable to human health and the environment. This standard's objective is to remove lead, mercury, cadmium, hexavalent chromium, polybrominated diphenyl ethers, and polybrominated diphenyl ethers from electrical and electronic goods, with an emphasis on cadmium concentration of less than 0.01%.

Why is RoHS Compliance Important?

The prohibited materials are environmentally harmful, contaminate landfills, and endanger employees during production and recycling. 

How is Printed Circuit Board Testing for RoHS Compliance?

Portable RoHS analyzers, also known as X-ray fluorescence or XRF metal analyzers, are used to check for and confirm the presence of prohibited metals. New testing is necessary to detect the amounts of these chemicals, which are extracted with a solvent, with the introduction of RoHS 3 and the four additional phthalates.

The testing process for the PCB sample is shown in the following figure:

Which Companies are Affected by the RoHS Directive?

If any of the banned materials are used, any company that sells or distributes applicable EEE (Electrical and Electronic Equipment) products, sub-assemblies, components, or cables directly to EU nations, or sells to resellers, distributors, or integrators who then sell goods to EU countries, is affected. Since RoHS-like rules have extended to many other nations, this simply no longer applies to EU countries. 

RoHS also applies to the metal industry for any application of metal plating, anodizing, chromatin, or other finishes on EEE components, heatsinks, or connectors.

For global PCB manufacturers, RoHS certification becomes a green transportation card. As I know of Chinese PCB companies, PCBgogo is a prominent RoHS-compliant PCB & PCB assembly manufacturer. They contribute to the elimination of hazardous chemicals from electronic goods by offering RoHS-compliant PCB manufacturing and PCB assembly services.

How is RoHS Directive Regulated in PCB Industry?

Let me comprehensively explain how the next generation of PCB products can meet the increasingly stringent environmental protection requirements from the aspects of raw materials management and selection.

1. Eco-friendly Raw Material Selection and Management

Hg, Cadmium, sexivalent chromium are seldom be used in the PCB industry, or it can be said, except for the wet process in PCB fabrication will residue trace amounts, this kind of element will not be used deliberately by PCB manufacturers. As a result, when select raw material, manufacturers only need to consider the content of lead and halogen does not exceed the standard to meet the environmental protection requirements. Actually, In PCB fabrication, surface finishes are the process to make the PCB lead-free.

2. Choose Lead-free Soldering

Traditional PCB (and SMT production) also has a great number of Pb-Sn ally, such as HAL, solder paste, which contents a lot of lead genus heavy metal elements. Once the body's lead inhalation exceeds its saturated concentration, symptoms such as anemia, calcium deficiency, and decreased immunity will occur.

With the worry for environmental pollution and the bad effect on human health, manufacturers only allowed panels or printing inks that have micro-scale halogens. 

Image courtesy: pcbgogo.com

2.1 The Selection of Materials

PCB final products include the following three types of materials: substrate materials, surface finishes (metal) layers, and inks.

2.1.1 Features of Eco-friendly Substrate Materials

Regularly panels contents FR-4, CEM-3 have a large number of brominated epoxy resin, such as tetrabromobisphenol, polybrominated biphenyls, polybrominated diphenyl ether. When burning, this material will emit extremely toxic substances, like dioxins (TCDO), benzofuran, etc. Once inhaled by the human will not be able to discharge and it would be a great threat to human health. As a result, materials that are used in the PCB CCL (Copper Clad Laminate) industry must be replaced by halogen-free substrate ( Cl<0.09%, Br <0.09% ), which means replacing brominated epoxy resin with phosphorous (P) containing epoxy resin, replacing the traditional dicyandiamide curing agent with nitrogen (N) containing phenolic resin.

Moreover, Environmental protection panel must have strong heat resistance capability to withstand high temperature that occurs many times in lead-free SMT project that may cause discoloration, delamination, deformation, and bend to the panel.

2.1.2 Avoid Polluted Environment by Correct Choice of Solder F luxes

Currently, most environmentally friendly solder fluxes use HASL, which replaced Pb-Sn alloy. The coating of lead-free PCBs should have high moisture liquidity, less thermal stress, and will not be easy to oxidize in high temperature, with these performances, the SMT process can be more stable. What’s more, HASL soldering flux should be environmentally recyclable and have miscibility with SMT soldering flux.

2.1.3 Attention to Residual Inks Pollution

Residual Inks in the PCB process include: solder resist inks, text inks, plug hole inks. The composition of inks is similar to panels, mainly including resin, bromine flame retardant, and curing agent. The selection of ink compliance to environmentally friendly requirements based on high thermal resistance capability and will not delaminate, drop, or crack in PCB productions.

2.1.4 Lead-free Materials Management

The management of substrate materials is the key link in the production chain. Disasters happen when a lead-tin bar is mistakenly added into a pure tin bath. At the same time, manufacturers won’t ignore indirect materials like soldering flux residuals. They always take the following measures to avoid this situation:

(1) Making lead-free and halogen-free raw materials coding rules.

(2) Use colorful slogan: the outer and inner packages are printed with "green environmental protection" label approved by IQA.

(3) Separately storing environmentally friendly raw materials, and these materials must be operated by trained staff.

(4) Completing authentication of the green qualified supplier.

Image courtesy: pcbgogo.com

Conclusion

Details determine success or failure. The same as PCB manufacturer. Good PCB comes from an employee-concerned manufacturer. RoHS directive not only guarantees PCB quality but also protects workers’ health. As a customer, RoHS certification always is a necessary reference. Wish everyone can find your loving RoHS-compliant PCB manufacturers.