What is RoHS 2 and Why is RoHS-Compliance Important?

RoHS stands for “Restriction of Hazardous Substances”. RoHS, also known as Directive 2002/95/EC, originated in the European Union and restricts the use of specific hazardous materials found in electrical and electronic products (EEP). All applicable products in the EU market after July 1, 2006 must pass RoHS compliance.

RoHS impacts the entire electronics industry and many electrical products as well. The original RoHS, often referred to as RoHS 1, was published in 2002 and took effect July 1, 2006. RoHS 2, or RoHS recast, was published in 2011 and took effect January 2, 2013. RoHS 2 addresses the same substances as the original directive while improving regulatory conditions and legal clarity.

Producing RoHS-Compliant PCBs is critical for several reasons:

1. Legal compliance – Selling non-compliant products in the EU is illegal and can result in heavy fines and penalties. Many other countries have also adopted similar RoHS regulations.

2. Environmental and health concerns – The hazardous substances restricted by RoHS can harm the environment and human health if not disposed of properly. Producing RoHS-compliant products helps protect the environment and people.

3. Market access – Many major markets including the EU require RoHS compliance. Producing compliant products ensures access to these key markets.

4. Customer demand – More and more customers are demanding environmentally friendly products. RoHS compliance helps meet this growing customer preference.

In summary, RoHS compliance is a must for any company producing EEPs for major world markets, especially the EU. It’s important from a legal, environmental, health, and business perspective.

Key Requirements of RoHS 2

The key RoHS 2 requirements that impact PCB production are:

1. Restricted materials: The use of lead (Pb), mercury (Hg), cadmium (Cd), hexavalent chromium (Cr6+), polybrominated biphenyls (PBB), polybrominated diphenyl ether (PBDE), and four different phthalates (DEHP, BBP, DBP, DIBP) is restricted to 0.1% or 1000 ppm, except for cadmium which is limited to 0.01% or 100 ppm, in each homogenous material that makes up the product.

2. CE marking: All products within scope must have the CE mark affixed to indicate compliance.

3. Declaration of Conformity (DoC): The DoC is a document that declares the product meets all relevant requirements. It must include information like a description of the product, a list of applicable directives, applied standards, and manufacturer info.

4. Technical documentation: Detailed technical documents must be maintained showing how the product complies with the applicable requirements. This may include material data sheets, test reports, risk assessments, etc.

While RoHS 2 introduced some new requirements compared to the original directive, the restricted substances and concentration limits remained the same. Properly managing these material restrictions in the PCB production process is key to ensuring compliance.

Strategies for Producing RoHS-Compliant PCBs

Producing RoHS 2 compliant PCBs requires careful control and management across the entire production process. Some key strategies include:

1. Review and Assess BOM

The Bill of Materials (BOM) should be carefully reviewed to identify any RoHS-restricted substances. Each material should be evaluated for RoHS compliance. Many component suppliers provide RoHS compliance data in material declarations or certificates of compliance.

Example BOM with RoHS compliance assessment:

Component	Supplier	RoHS Compliant?
PCB Laminate	ABC Co.	Yes – per supplier CoC
Solder paste	XYZCo.	Yes – lead-free composition
SMD capacitors	123 Inc.	Yes – RoHS-compliant series
TQFP ICs	Acme Co.	Need more info – request material declaration

Any components with unknown RoHS status should be investigated further with the supplier. Non-compliant parts should be replaced with RoHS-compliant alternatives where possible.

2. Select RoHS-Compliant Materials and Processes

When choosing materials for PCB Fabrication, RoHS compliance should be a key consideration. This applies to laminate materials, solder masks, surface finishes, inks, adhesives, etc. Many standard PCB materials are available in RoHS-compliant versions.

Example RoHS-compliant PCB materials:

Material Type	Examples
PCB laminate	FR-4, polyimide, halogen-free
Solder mask	LPI, SMOBC, UV cured
Surface finish	ENIG, OSP, immersion silver, immersion tin
Solder	SAC305, SN100C

Manufacturing processes should also be evaluated. Some older processes may introduce RoHS-restricted substances even if compliant materials are used. For example, chromate conversion coatings can introduce hexavalent chromium.

3. Manage Supply Chain

The supply chain must be managed to ensure only RoHS-compliant materials and components enter the production process. This includes:

• Selecting and approving suppliers that can provide RoHS-compliant materials
• Obtaining material declarations, certificates of compliance, or full material disclosures from suppliers
• Incoming inspection and testing to verify RoHS compliance of delivered materials
• Proper material storage and handling to avoid contamination
• Tracking and documenting the RoHS compliance status of all inventoried materials

An effective supplier management and material traceability system is key to maintaining the integrity of RoHS compliance efforts across a complex supply chain.

4. Control the Production Process

The PCB production process must be controlled to ensure RoHS compliance is maintained. Some key control points include:

• Process chemistries – Ensure all chemicals and process solutions are RoHS-compliant. This includes plating chemistries, cleaners, etchants, fluxes, etc.

• Lead-free soldering – Use of lead-free solder alloys and compatible soldering processes. May require adjustments to soldering temperature profiles, equipment settings, etc.

• Contamination control – Implement procedures to prevent contamination of RoHS-compliant assemblies with restricted substances. This may include designated production lines, cleaning procedures, protective storage, etc.

• Process monitoring – Regularly monitor the production process to ensure control points are effective. This can include chemical analysis of process baths, XRF screening of materials and assemblies, visual inspections, etc.

Effective production controls, along with the use of compliant materials, helps ensure the final product will meet RoHS requirements.

5. Verify and Document Compliance

Finished PCBs should be verified for RoHS compliance before shipment. A combination of techniques can be used:

• X-ray Fluorescence (XRF) – A non-destructive technique that can measure the elemental composition of materials. Useful for screening for the presence of restricted substances.

• Lab analysis – Destructive testing where samples are digested in acid and analyzed using techniques like ICP-OES, AAS, UV-VIS, etc. Provides more definitive determination of restricted substance concentration but is slower and consumes the sample.

• Supplier declarations – Collection and review of RoHS compliance declarations for all materials and components used in the final product.

Compliance should be documented as part of the technical file for the product. Documentation may include:

• BOM with RoHS compliance status noted
• Supplier declarations of conformity
• Material test reports
• XRF screening or lab analysis reports
• Description of RoHS control processes used in production

Maintaining complete and organized compliance documentation is important to demonstrate due diligence and support a Declaration of Conformity.

FAQ on Producing RoHS 2 Compliant PCBs

What are the consequences of non-compliance?

Selling non-RoHS compliant products in the EU can result in the product being blocked from the market, recalls of non-compliant products already sold, and fines or legal penalties for the producer. Non-compliance can also damage a company’s reputation with customers.

Are any exemptions allowed under RoHS 2?

Yes, RoHS 2 allows for certain exemptions where elimination of the restricted substances is technically or scientifically impractical. Examples include lead in high melting temperature type solders, lead in glass of electronic components, and cadmium in photoresistors. The list of exemptions is periodically reviewed and updated.

How do I know if my components are RoHS-compliant?

The best way is to obtain material declarations or certificates of compliance from your component suppliers. Many suppliers make this information readily available. If not available, you may need to contact the supplier directly and request compliance documentation. In some cases, component testing may be necessary if supplier data is unavailable.

What if I can’t find a RoHS-compliant alternative for a component?

If a non-compliant component is necessary for technical reasons, first check if it falls under any of the RoHS exemptions. If not, you may need to apply for a new exemption. This involves making a case to the European Chemicals Agency that the use is necessary and substitution is not currently possible. Exemptions are reviewed and are time-limited if granted.

How often do I need to update my RoHS compliance documentation?

Compliance documentation should be reviewed and updated any time there is a significant change that could impact RoHS compliance status. This could include changing component suppliers, material compositions, production processes, etc. Even if no major changes occur, it’s a good practice to periodically review documentation to ensure it’s current. An annual review is a common approach.

Producing RoHS 2 compliant PCBs requires a comprehensive approach that addresses materials, processes, and documentation across the product lifecycle. By carefully selecting compliant materials, controlling the production process, and maintaining organized compliance records, PCB Manufacturers can ensure their products meet the evolving demands of RoHS and access global markets.