How an EU PFAS Ban Will Affect Your PCBs

 

Background on PFAS Chemistry

PFAS (per- and polyfluoroalkyl substances) refer to a group of over 4000 human-made chemicals containing fluorine and carbon atoms. The carbon-fluorine bonds provide unique properties like oil, stain, and water repellency.

PFAS have been widely used since the 1950s in products like:

• Non-stick cookware (Teflon)
• Stain resistant coatings
• Food packaging
• Firefighting foams
• Electronics

However, PFAS persist indefinitely in the environment and can accumulate in the body. Health concerns over PFAS have grown in recent years.

PFAS Usage in PCBs

In PCB fabrication, PFAS chemistries provide important functions:

• Photoresist - Development surfactants enable removal of cross-linked resist after imaging.
• Solder mask - Fluoropolymers create low-friction, protective solder mask.
• Conformal coatings - Flourinated coatings safeguard against moisture, chemicals, and dust.
• Plating - Mist suppressants containing PFAS minimize plating defects.

While PFAS make up a tiny fraction of the final board, they are currently essential in fabrication. Eliminating PFAS would require major changes in materials and processes.

EU Environmental Regulations

The European Union has enacted increasingly strict environmental regulations on PFAS and other hazardous substances:

• REACH - Registration, Evaluation, Authorization and Restriction of Chemicals regulation restricts chemicals of concern. PFAS are a target.
• RoHS - Restriction of Hazardous Substances in Electrical and Electronic Equipment bans certain substances in electronics.
• WEEE - Waste Electrical and Electronic Equipment directive mandates recycling of electronics to recover valuable materials and prevent improper disposal.
• ELV - End-of-life Vehicles directive requires removing hazardous materials like PCBs during auto recycling.

Compliance with EU regulations is mandatory for electronics sold in the EU market. A full PFAS ban would profoundly impact PCB manufacturing.

Proposed EU PFAS Regulation

In April 2022, the European Chemicals Agency (ECHA) proposed:

• Banning nearly all intentional uses of PFAS by 2025.
• Restricting PFAS contamination in products to low ppm levels.

Only certain essential uses with no substitutes could continue until 2030.

This would completely prohibit most PFAS usage in PCB fabrication and severely limit allowable contamination levels.

Effects of a PFAS Ban on PCBs

If enacted as proposed, a PFAS ban in the EU would force major changes for PCB manufacturing:

Photoresist

• Alternative surfactants would replace fluorosurfactants in photoresist developers.
• Resist stripping and legacy cross-linked resist removal would need new formulations.
• More aggressive stripping chemistry may be required, risking copper attack.

Solder Mask

• Fluoropolymer-based solder mask materials could no longer be used, removing properties like low friction, chemical inertness, and heat resistance.
• Instead, epoxy-based or other polymeric masks would become standard. However, these alternative masks have limitations in key parameters.

Conformal Coatings

• Fluorinated conformal coatings offer the best protection against moisture, chemicals, abrasion, and temperature extremes. Ban compliant alternatives cannot match their performance.
• Product reliability could suffer, especially in demanding applications.

Plating

• Current PFAS-containing plating mist suppressants would need replacing with inferior performing products.
• An increase in plating defects like pitting could occur as a result.

Costs

• Substituting chemicals, changing materials, and qualifying new processes will add costs throughout the PCB supply chain.
• Inevitably, higher PCB prices will impact end products containing boards.
• Economic impacts on the European PCB industry could be severe long-term if regulations put them at a global disadvantage.

Potential Solutions

Facing a PFAS ban, PCB manufacturers have several options:

Reformulation

• Work closely with chemical suppliers to reformulate materials like photoresist, solder mask, and conformal coatings using non-fluorinated alternatives.
• Engage with plating chemistry providers to develop effective mist suppressants without PFAS.
• Extensively test new formulations for performance and optimize processes.

Legacy PFAS Removal

• Invest in equipment and chemistry to reliably remove all traces of legacy PFAS contamination.
• Upgrade waste treatment to actively filter out PFAS before water discharge.

Geographic Shifting

• Transfer production requiring PFAS chemicals to facilities outside the EU.
• Import those PCBs into EU markets to meet customer needs.

Process Innovation

• Develop innovative methods not reliant on PFAS, such as moving to dry film solder mask or inkjet printing.
• Pioneer new plating equipment that eliminates the need for mist suppressants.
• Utilize emerging technologies like plasma surface treatments to replace legacy chemistries.

Design Compensation

• Incorporate more tolerance for defects into PCB designs.
• Use larger spacing and higher reliability components to compensate for process weaknesses.
• Overdesign end products to counteract potential PCB defects escaping to field use.

With substantial effort and investment into proactive solutions, the industry can adapt to survive an EU PFAS ban.

Potential Impact on PCB Quality

Despite best efforts, a PFAS ban may degrade quality and reliability:

• More frequent copper etching defects due to harsher resist stripping chemistry.
• Increased risk of electrochemical migration on boards without top-performing solder masks.
• Lower yields as alternative plating chemistries cause pitting and imperfections.
• Reduced power density capabilities as inferior thermal management materials limit performance.
• Shorter product lifespan from condensation and ingression without fluoropolymers' protection.

Unfortunately, some quality reduction may be unavoidable. Extra design vigilance would be needed to ensure product reliability.

Impact on PCB Costs

Even with significant process changes, PCB costs would rise:

• Expensive new capital equipment required for legacy PFAS removal and alternative processes.
• Higher cost of PFAS substitutes versus established chemicals.
• Increased scrap and rework due to process defects from new materials.
• Extended process cycle times until optimized with substitutes.
• Ongoing qualification testing of new chemicals and procedures.

These factors mean a major cost increase is inevitable for PFAS-free PCBs in Europe.

Questions on PFAS Health Risks

Some experts question whether a blanket PFAS ban is justified based on uncertain health risks:

• PFAS levels in PCBs contribute negligibly to overall human exposure.
• No evidence directly links PCB PFAS to health issues.
• Potential substitutes may pose their own unforeseen health hazards.
• Low PFAS exposures today may be safer than making sweeping changes.

There are arguments that continuing restricted critical usage of well-studied PFAS compounds does not pose substantial or imminent health risks. It is unclear whether near-zero traces of PFAS in PCBs warrant a total ban.

Case Against EU PFAS Regulations

Reasons exist to challenge the proposed EU PFAS ban:

• Severe negative impact on European PCB industry competitiveness and viability.
• Marginal reduction in overall PFAS exposures given minute usage in PCBs.
• Excessive regulation without definitive proof of health risks.
• PCB performance and reliability degradations affecting all products containing boards.
• Increased electronics costs for EU consumers and companies ultimately.
• Loss of PFAS expertise and intellectual property in Europe as industries relocate outside EU.

The electronics industry may resist the EU proposals as excessive and unwarranted. But if enacted, manufacturers must engage and adapt.

Preparing for a PFAS Ban

Given the likelihood of eventual EU restrictions, PCB companies should begin preparing now:

• Audit PFAS usage in manufacturing processes and supply chain.
• Research alternative materials for a PFAS-free process.
• Start testing replacements like solder masks and conformal coatings.
• Evaluate capital investment needed for new equipment and legacy PFAS removal.
• Analyze change management requirements and retraining needs.
• Consult with PCB partners and suppliers on best practices.
• Provide feedback to regulators on realistic timelines and critical uses.
• Model the commercial viability impact of increased costs.

With advanced planning, companies can mitigate disruptions from the forthcoming EU PFAS regulations.

FAQs

What are some alternative solder mask materials?

Epoxy, silicone, polyurethane, and other polymeric resins can replace fluoropolymers but with limitations in performance. Hybrid solder masks are under development to bridge the gap.

How soon could a ban take effect?

The proposals may still change but an EU ban on most PFAS use could occur by 2025. Some essential uses may be exempt until 2030.

Can PCB manufacturers apply for exemptions?

Potentially, for specific applications deemed critical and irreplaceable. But the approval criteria will be extremely stringent.

Will PFAS be banned in PCBs manufactured outside Europe?

Initially no, unless those countries follow Europe's lead in severely restricting PFAS. But multinationals may eventually transition away from PFAS globally.

What is the most promising PFAS-free alternative process?

Dry film solder mask and inkjet printing appear well suited for high reliability PCBs without liquid photoimageable masking relying on fluoropolymers.