PFAS (Per- and polyfluoroalkyl substances) for Printed circuit board (PCB)

Printed circuit board (PCB)

สาร PFAS คือ สารเคมีที่ทนทานต่อความร้อน น้ำ และน้ำมัน

ซึ่งถูกนำไปใช้ในผลิตภัณฑ์หลากหลายชนิด เช่น บรรจุภัณฑ์อาหาร อุปกรณ์ทำครัว และเครื่องสำอาง

1. PFAS Checklist for PCB Manufacturing

A. PFAS Sources in PCB Production

✅ Solder Masks & Coatings

• Fluoropolymer-based (PTFE, FEP, PFA).

• Check MSDS for PFAS content.✅ Conformal Coatings

• Waterproofing/anti-corrosion layers.✅ Fluxes & Cleaning Agents

• PFAS may be in surfactants.✅ Laminates & Substrates

• Some high-frequency PCBs use PTFE (e.g., Rogers RO3000 series).✅ Plating & Etching Chemicals

• PFAS in wetting agents or anti-foaming additives.

B. Process Steps to Audit

Process Stage	PFAS Risk	Test Method (If Suspected)
Substrate Prep	PTFE laminates	FTIR, XRF (screening)
Solder Mask Application	Fluoropolymer coatings	LC-MS/MS (extraction)
Plating/Etching	PFAS in surfactants	EPA 1633 (water/chemical analysis)
Conformal Coating	PFAS-based sprays	GC-MS (volatile PFAS)
Final Cleaning	PFAS in solvents	TOP Assay (precursor breakdown)

2. Typical PFAS Test Results in PCBs

A. Lab Testing Data (Example)

Sample	PFAS Detected	Concentration (ppm)	Source
Solder Mask	PFOA	0.02	Fluoropolymer residue
Etching Wastewater	PFOS	0.15	Surfactant degradation
PTFE Laminate	PTFE (polymer)	>1000	Substrate material
Conformal Coating	6:2 FTOH	0.5	Waterproofing agent

B. Interpretation

• >1 ppm PFAS: Likely intentional use (e.g., PTFE substrates).

• <1 ppm PFAS: Contamination (e.g., from coatings or cleaning agents).

• Non-detect (ND): PFAS-free alternatives used.

3. Mitigation Strategies

A. PFAS-Free Alternatives

• Solder Masks: Silicone/epoxy-based coatings.

• Substrates: Polyimide (instead of PTFE) for high-frequency PCBs.

• Fluxes: Citric acid-based (no PFAS surfactants).

B. Process Changes

• Replace PFAS-containing conformal coatings with acrylic/parylene.

• Use PFAS-free etching agents (e.g., peroxide-based).

• Implement wastewater treatment (activated carbon, ion exchange).

C. Compliance Steps

1. Supplier Audits: Require PFAS declarations for all chemicals/materials.

2. Routine Testing: Quarterly LC-MS/MS for high-risk processes.

3. Documentation: Align with IEC 62321 (electronics hazardous substances).

4. Regulatory & Industry Standards

Standard	Applicability	PFAS Focus
EPA 1633	Wastewater/soil	40+ PFAS compounds
IEC 62321-12	Electronics	PFAS in materials
EU REACH	PCBs sold in EU	PFOS/PFOA restrictions
JPCA-ES-01-2019 (Japan)	PCB industry	Voluntary PFAS limits

5. Testing Labs for PCBs

• Commercial Labs:

  • Eurofins (PFAS in materials/wastewater).

  • SGS (IEC 62321 compliance).

  • Pace Analytical (EPA 1633 for PCBs).

• In-House Screening:

  • XRF (for total fluorine).

  • FTIR (PTFE/fluoropolymer detection).

6. Example Compliance Report

Company X PCB Audit (2024)

• Findings: PFOS detected in etching wastewater (0.2 ppm).

• Action Taken: Switched to PFAS-free wetting agent; retested ND.

• Certification: IEC 62321 compliant for PFAS.

Key Takeaways

✔ Test high-risk materials (solder masks, coatings, laminates).✔ Prioritize wastewater (PFAS accumulates in effluent).✔ Adopt PFAS-free alternatives to meet future bans (e.g., EU 2025).