Aller au contenu Kangchuang Paper’s SMD bracket packaging paper is a precision-manufactured sulfur-free paper engineered specifically to protect silver-plated SMD brackets, LED lead frames, gold-plated terminals, and copper-based electronic components from tarnish and oxidation during manufacturing, inter-facility transit, and long-term storage. With sulfur content controlled below 5ppm — the critical threshold at which hydrogen sulfide gas begins to tarnish silver and copper surfaces — our bracket packaging paper provides a chemically inert wrapping layer that prevents the electrochemical oxidation reaction that discolors plated metal contacts and reduces component solderability. Available in custom roll widths from 20mm to 1,200mm, in paper weights from 35gsm to 120gsm, shipped via DHL Express to electronics manufacturers in the United States, free sample rolls on request.
Surface-mount device (SMD) brackets — the silver-plated or gold-plated metal frames that hold LED chips, integrated circuits, and passive components — are among the most tarnish-sensitive materials handled in electronics manufacturing. Silver plating, used on brackets for its optical reflectivity (critical for LED luminous efficiency) and electrical conductivity, reacts rapidly with hydrogen sulfide (H₂S) gas to form silver sulfide (Ag₂S), a dark brown-to-black tarnish compound that significantly degrades both the optical and electrical performance of the component.
The critical and often overlooked fact is that standard packaging paper — kraft paper, newsprint, standard tissue — contains sulfur compounds from the kraft pulping process (sulfate pulping uses sodium sulfide as a cooking chemical) that off-gas hydrogen sulfide under normal storage conditions. When silver-plated components are wrapped in or stored with standard paper, the H₂S released by the paper reacts directly with the silver surfaces, producing visible tarnish that can form in as little as 24–72 hours at room temperature in a sealed package.
This is why electronics manufacturers purchasing SMD brackets, LED packages, silver-plated connectors, and copper-base components specify low-sulfur or sulfur-free packaging paper as a mandatory packaging material requirement — not as a premium option, but as a basic protection specification.
The <5ppm sulfur content specification for electronics-grade packaging paper is derived from empirical data on the sulfide gas emission rates of paper at various sulfur concentrations and the reaction kinetics of silver tarnishing at room temperature. At sulfur concentrations above 5ppm in the paper, detectable H₂S off-gassing occurs at ambient conditions sufficient to produce observable tarnish on silver surfaces within weeks. Below 5ppm, H₂S emission rates from the paper are low enough that standard shelf life periods (12–24 months) do not produce significant tarnish on properly packaged components.
Kangchuang’s SMD bracket packaging paper is produced from select pulp grades with sulfur content controlled through the manufacturing process, with final sulfur content verified by batch-level XRF (X-ray fluorescence) testing and wet chemical analysis. Test reports documenting sulfur content are available for every production lot — essential for component manufacturers qualifying packaging materials under IPC, JEDEC, or customer-specific packaging standards.
LED Package Interleaving: Between layers of SMD LED packages in bulk trays — preventing tarnish on silver-plated reflector cups, lead frames, and bond wire surfaces during inter-facility shipment and storage before assembly.
Connector and Terminal Packaging: Wrapping silver-plated and tin-plated connectors, terminals, and contact assemblies for transit packaging where exposure to H₂S from standard packaging materials would cause tarnish that compromises electrical contact resistance.
Component Reel Paper: Slit to carrier tape widths for use as the cover paper or spacer paper in tape-and-reel packaging of SMD brackets and LED components, providing a sulfur-free separation layer between component rows.
Bulk Hardware Wrapping: Wrapping silver-plated hardware, electroplated screws, and precision metal parts where surface finish preservation is required during long-term storage or ocean freight transit.
| SPECIFICATION | DETAILS |
| Sulfur Content | <5ppm — XRF and wet chemical analysis verified per batch |
| Paper Weight Range | 35gsm to 120gsm — multiple grades available |
| pH Value | 7.0–8.5 (acid-free, slightly alkaline reserve) |
| Roll Width Range | 20mm to 1,200mm — custom slit to specified width |
| Width Tolerance | ±0.5mm for widths up to 500mm | ±1.0mm for widths 500–1,200mm |
| Surface | Smooth, calendered — low lint, low particle generation |
| Color | Natural white (bleached pulp) — standard | Kraft (unbleached) — on request |
| Core Inner Diameter | 3-inch (76mm) standard | 6-inch (152mm) | Custom on request |
| Maximum Roll OD | 800mm standard | 1,200mm on request |
| Roll Length | Customer-specified | Typical: 1,000m–5,000m per roll |
| Moisture Content | 6–8% equilibrium at 23°C / 50% RH |
| Tensile Strength | ≥1.5 kN/m (MD) — sufficient for automated reel feeding without tearing |
| MOQ | 2 rolls for sample evaluation | 500kg minimum for production orders |
| Lead Time | 5–7 business days (samples) | 7–12 business days (production) |
| Shipping | DHL Express (USA samples free) | Sea freight FOB Dongguan (production orders) |
| Documentation | Sulfur test report | Batch certificate | Material safety data sheet |
SMD bracket packaging paper is a specialty paper used to wrap, interleave, or line packages containing surface-mount device (SMD) brackets — the silver-plated or gold-plated metal frames that hold LED chips, integrated circuits, and other electronic components. It must be sulfur-free because standard paper contains residual sulfur compounds from the kraft pulping process that off-gas hydrogen sulfide under ambient conditions. This H₂S reacts with silver and copper surfaces to form metal sulfide tarnish, which degrades the optical reflectivity of LED reflector cups and the solderability of plated terminals. Electronics-grade packaging paper with <5ppm sulfur content prevents this reaction during storage and shipment.
The 5ppm (parts per million) sulfur specification means that the paper contains less than 5 micrograms of sulfur per gram of paper. At this concentration, the rate of hydrogen sulfide gas emission from the paper under normal ambient conditions (23°C, 50% relative humidity) is low enough that silver and copper surfaces in contact with or enclosed near the paper will not develop detectable tarnish during the standard shelf life period of 12–24 months. Above 5ppm sulfur, measurable tarnish on silver surfaces can form in weeks. We verify sulfur content by XRF analysis on every production batch and provide test reports with shipments.
Regular acid-free paper is defined by its pH (neutral or alkaline, no acidic degradation products), but acid-free does not mean low-sulfur. Many acid-free papers are produced by alkaline papermaking but still contain sulfur residues from pulping chemicals. Kangchuang’s SMD bracket packaging paper is both acid-free (pH 7.0–8.5) AND low-sulfur (<5ppm), with sulfur content specifically controlled and tested — not just assumed from the papermaking method. This dual specification is what makes it suitable for silver and copper component protection, where acid-free alone is not sufficient.
Yes. We regularly supply SMD bracket packaging paper slit to standard component carrier tape widths: 8mm, 12mm, 16mm, 24mm, 32mm, and 44mm for EIA-481 standard tape-and-reel applications, as well as custom widths for proprietary packaging systems. Width tolerance for carrier tape applications is ±0.3mm, achieved through precision razor blade slitting with calibrated blade setup. Please specify the carrier tape standard (EIA-481, JEDEC, or customer-specific) and component type when ordering so we can recommend the appropriate paper grade and caliper.
The appropriate paper weight depends on the application. For lightweight interleaving between component layers in trays: 35–50gsm provides a thin, flexible separation layer without adding significant bulk. For wrapping individual component assemblies for transit protection: 60–80gsm provides better tear resistance and handling durability. For heavy-component bulk wrapping where mechanical protection is needed alongside tarnish prevention: 80–120gsm. We can recommend a specific grade based on your component type, packaging method, and storage period — contact us with your application details.
Yes — sulfur test reports are standard for all SMD bracket packaging paper orders, not an optional add-on. Each batch of paper is sampled and tested by XRF analysis in our quality laboratory before the batch is approved for slitting and shipment. The test report documents the batch number, production date, measured sulfur content (in ppm), measurement method, and the specification limit (<5ppm). For customers requiring third-party laboratory verification, we can arrange independent testing at an accredited laboratory — please request this when placing your order as it adds lead time.
While silver tarnish from sulfide gases is more visually dramatic and commonly discussed, gold-plated surfaces are also vulnerable to contamination from paper-sourced chemicals, particularly acidic gases and ionic contaminants that degrade solderability even on gold. Our sulfur-free, acid-free bracket packaging paper protects gold-plated surfaces from ionic contamination and surface chemistry changes that affect bonding and soldering performance. The same specification (<5ppm sulfur, pH 7.0–8.5) applies for gold-plated component protection.
Our SMD bracket packaging paper has a recommended storage life of 24 months from production date when stored under standard conditions: 15–30°C, 30–65% relative humidity, away from direct sunlight and chemical storage. After 24 months, we recommend re-testing the paper’s sulfur content before use in sensitive component packaging, as slow sulfur migration from adjacent materials or aging effects on the paper chemistry can occur in some storage environments. Store rolls in their original polyethylene wrapping until use to maintain the moisture and contamination barrier.
Yes — we supply a white antistatic sulfur-free paper that combines <5ppm sulfur content with measured surface resistance of 10⁷–10¹⁰ Ω/sq for ESD-sensitive component protection. This grade is suitable for applications where both tarnish prevention and electrostatic discharge protection are required — common in mixed-signal IC packaging, MEMS device handling, and sensitive sensor component wrapping. See our White Antistatic Sulfur-Free Paper product page for full specifications.
Sample evaluation orders have a minimum of 2 rolls per specified width — with no minimum total weight for sample orders. Samples are shipped via DHL Express at no charge to your US facility, typically within 5–7 business days of your specification being confirmed. Production orders have a minimum of 500kg total weight across all specified grades and widths.
Custom printing on SMD bracket packaging paper is available for orders above 3,000kg. Typical custom printing includes company name, product code, handling instructions (e.g., ‘Sulfur-Free — Electronics Grade’), and warning symbols. Print chemistry is selected to be compatible with the anti-tarnish properties of the paper — not all printing inks are sulfur-free, so we verify ink sulfur content before use on electronics-grade paper. Contact us with your artwork requirements and order volume for a printing quotation.
Yes. We ship regularly to electronics manufacturers, LED assembly operations, connector producers, and contract packaging companies throughout the United States. Sample rolls are shipped via DHL Express (3–5 business days to most US locations) at no cost. Production orders ship FOB Dongguan by sea freight with full export documentation. We can provide a delivered cost estimate to your US facility — contact us with your specification and US delivery address.
Kangchuang Paper specializes in high-quality industrial papers — sulfur-free, coated, release, and anti-rust. Tell us your requirements and we’ll recommend the right grade with fast turnaround.
