Top 5 Brands Offering High-Quality Sulfur-Free Paper for PCBs
In today’s high-precision printed circuit board (PCB) manufacturing industry, selecting the right materials for storage, handling, and transportation is more critical than ever. One often-overlooked but essential material is sulfur-free paper — a specialty industrial paper designed to minimize corrosion, tarnish, and contamination risks for silver, copper, and other metal-plated surfaces. This article explains the importance of sulfur-free paper in PCB manufacturing, highlights key selection criteria, and introduces five well-known brands or suppliers offering high-quality sulfur-free paper for PCB and electronics applications.
Why Sulfur-Free Paper Matters for PCBs
In PCB manufacturing, many boards are silver-plated, copper-plated, or treated with other metal finishes that are susceptible to sulfide corrosion and tarnishing. For example, when silver encounters hydrogen sulfide or sulfur ions in the environment, silver sulfide (Ag₂S) can form — a dark compound that can impair solder pads, conductivity, and overall reliability.
Sulfur-free paper is specified to have extremely low sulfur and chloride content (e.g., sulfur ≤50 ppm) and is used as interleaving, separation, or packaging material to prevent metal surfaces from contacting reactive sulfur species.
In addition to corrosion protection, high-quality sulfur-free paper is suitable for cleanroom, ESD-safe, and low-dust environments, making it ideal for modern electronics manufacturing.
Key Criteria When Selecting Sulfur-Free Paper
When choosing sulfur-free paper for PCB applications, consider the following:
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Sulfur and Chloride Content: Reputable products indicate very low sulfur levels, often tested to SGS or equivalent standards (e.g., sulfur dioxide ≤50 ppm).
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Chemical Purity and Compliance: High-quality papers are free from chlorine (Cl), lead (Pb), cadmium (Cd), mercury (Hg), hexavalent chromium (Cr VI), and other hazardous substances, and comply with RoHS or similar regulations.
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Physical Cleanliness: Paper used for PCBs and electronic products should be dust-free, lint-free, and non-abrasive, and produced in a controlled environment (e.g., Class 100/1000 cleanroom).
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Neutral or Acid-Free pH: For long-term storage or sensitive metal finishes, acid-free or near-neutral pH prevents yellowing, off-gassing, or chemical reactions with plating.
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Grammage and Format: Applications often require specific weights (e.g., 60 g/m², 70 g/m², 120 g/m²) and custom sizes to fit PCB stacks, trays, or packaging.
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Storage and Handling Requirements: Proper storage conditions (18–25 °C, dry warehouse, away from sunlight and moisture) preserve paper quality.
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Supply Chain, Customization, and Technical Support: Reliable suppliers offer custom widths, slitting, cut-sheet or roll formats, and understand PCB/electronics customer requirements.
By evaluating these factors, manufacturers and assemblers can select paper that effectively protects plated boards, maintains solderability, and improves yield and reliability.
Top 5 Brands / Suppliers of Sulfur-Free Paper for PCB Applications
1. Dongguan Kangchuang Paper Co., Ltd. (KCZY)
Kangchuang Paper is a professional supplier of sulfur-free paper for PCB and electronics manufacturing, with notable advantages in quality control, customization, and industry expertise:
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Strict Low-Sulfur Standards: Extremely low sulfur content meets the requirements of silver, copper, and gold plating, preventing corrosion and discoloration.
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Clean Production and Consistent Physical Properties: Produced in dust-free workshops, the paper is lint-free, uniform in texture, and suitable for cleanroom environments.
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Customizable Specifications: Supports different grammages, roll widths, sheet cutting, and slitting services for PCB trays, stacks, and electronic component packaging.
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Environmental Compliance and Technical Support: Complies with RoHS standards and provides datasheets, test reports, and technical assistance.
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Reliable Supply Chain: Stable production and export experience meet long-term bulk purchasing requirements.
Recommendation: Choosing Kangchuang sulfur-free paper ensures effective protection for PCB metal surfaces, consistent paper quality, and flexible customization, making it an ideal partner for PCB manufacturers and electronics component suppliers.
2. Daubert Cromwell, Inc. – Silver Saver® Anti-Tarnish Paper
A U.S.-based supplier offering VCI (Volatile Corrosion Inhibitor) and specialty packaging papers. The Silver Saver® paper is explicitly sulfur-free, protecting silver, gold, and noble-metal plated components without affecting solderability, conductivity, or surface resistivity.
3. Suzhou Huashang Paper Co., Ltd.
Offers sulfur-free paper with sulfur content <50 mg/kg (SGS tested), suitable for high-end PCB substrate protection, photovoltaic cell separation, and similar applications. Production in dust-free workshops ensures quality for high-end PCB environments.
4. Xinyuanshun Paper Co., Ltd. – Anti-Oxidation Sulfur-Free Paper
Serves electronics, metal stamping, and finished goods packaging, emphasizing acid-free, sulfur-free paper available in customizable widths and thicknesses. Offers broad application possibilities and supports special customization needs.
5. B&T Purify (BTPurify / Bei Te)
Specializes in industrial sulfur-free paper for PCB silver-plated packaging. Complies with RoHS and specifies sulfur dioxide ≤50 ppm. Suitable for PCB anti-tarnish packaging and offers cost-effective solutions.
Conclusion
In PCB and electronics manufacturing, even minor differences in interleaving or packaging materials can significantly impact yield, reliability, and costs. Choosing high-quality sulfur-free paper, such as that offered by Kangchuang Paper, effectively protects metal-plated surfaces, maintains solderability, and meets strict quality standards, while providing stable supply, technical support, and flexible customization.