| HS Code | 378950 |
| Product Name | PCB Pad Protectant (BASF Pad Protectant) Electronic/EL Grade |
| Chemical Class | Water-based organic coating/protectant formulation |
| Form | Liquid |
| Color | Clear, colorless to pale yellow |
| Odor | Mild, characteristic |
| Ph As Supplied | 6.0 - 8.0 |
| Specific Gravity 20c | 1.00 - 1.05 |
| Boiling Point | Approximately 100 C (212 F) |
| Flash Point | None to boiling / non-flammable |
| Solubility In Water | Miscible |
| Vapor Pressure 20c | Approximately 2.3 kPa (17 mmHg) |
| Voc Content | Less than 1% |
| Shelf Life | 12 months in original sealed container at 5-35 C |
As an accredited PCB Pad Protectant (BASF Pad Protectant) Electronic/EL Grade factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | Packaged as 1 L of BASF PCB Pad Protectant (electronic/EL grade) in a sealed, labeled HDPE container for high-purity applications. |
| Container Loading (20′ FCL) | One 20′ FCL container loaded with BASF PCB Pad Protectant (EL grade), securely packed, braced, and sealed for safe transport. |
| Shipping | Shipping of PCB Pad Protectant (BASF Pad Protectant, Electronic/EL Grade) requires secure, tightly sealed containers to prevent leakage. Maintain ambient temperatures, avoid moisture and direct sunlight. This material is generally non-hazardous for transport, but should be shipped ground within protective packaging. Include proper documentation, handling labels, and avoid incompatible materials during transit. |
| Storage | Store in a tightly sealed original container in a cool, dry, well-ventilated area away from direct sunlight, heat, sparks, and open flames. Avoid contact with strong oxidizers and prevent moisture ingress or contamination. Keep container upright and closed when not in use. Follow manufacturer’s specified temperature range and shelf-life guidelines. |
| Shelf Life | Store PCB Pad Protectant unopened in its original container at room temperature; shelf life is 12 months when kept dry, sealed, and away from heat. |
Double-sided reflow assembly of automotive engine control units built on mid-Tg FR-4 or halogen-free laminates begins with a horizontal immersion organic solderability preservative line in which the BASF Pad Protectant Electronic/EL Grade concentrate is charged at 18–22 vol% into deionized water having resistivity not less than 18 MΩ·cm at 25 °C. The working bath pH is maintained at 2.8–3.2 with temperature-compensated glass electrode control, and bath temperature is held at 38–42 °C during a 45–75 s contact window. The preceding microetch step operates as a conveyorized spray at 1.2–1.8 m/min, removing 1.2–1.8 μm of copper with sodium persulfate controlled against cupric ion loading not exceeding 25 g/L as Cu²⁺; excessive etch depth beyond 2.0 μm has been associated with pad coplanarity deviations above 25 μm on 0.4 mm pitch QFN lands. Forced-air drying at 65–80 °C for 60–120 s reduces residual surface moisture below 0.1% by near-infrared reflectance before board stacking. In subsequent SMT printing, type 4 SAC305 solder paste per J-STD-005 is applied through lasered stainless-steel stencils with aperture area ratios not less than 0.66, followed by reflow profiling under J-STD-020D with peak temperature 240–245 °C and time above liquidus 60–90 s. The organic film decomposes during reflow and permits wetting to satisfy solderability requirements of J-STD-003, while ionic cleanliness after assembly is verified by IPC-TM-650 2.3.25 to remain below 1.56 μg/cm² NaCl equivalent. The terminal assembly is an IATF 16949-certified engine control unit compliant with RoHS 2011/65/EU and the REACH candidate-list requirements applicable to electronic-grade process chemistries.
The mixed-technology wave soldering window on high-layer-count telecom line cards is constrained primarily by residual film thickness at the through-hole barrel exit and by flux solids loading in the no-clean wave flux. Boards processed with the BASF Pad Protectant Electronic/EL Grade working bath at 20 vol%, 39 °C, and 60 s immersion time typically show dry film thickness of 0.20–0.30 μm on exposed copper pads and through-hole rims. A thickness above 0.40 μm has been observed in production to delay wetting initiation beyond 2.0 s at 260 °C solder pot temperature, producing plated-through-hole fill below the 75% minimum specified in IPC-A-610 class 2 for through-hole solder joints. The flux selected for this mixed-technology configuration is an alcohol-based low-solids no-clean formulation with solids content of 2.0–3.5 wt% and classification ORL0 per J-STD-004B; lower solids are inadequate to activate copper beneath thicker organic films, while higher solids leave visible post-wave residues on SMT components mounted on the top side. Top-side preheat is maintained at 95–115 °C, solder pot temperature at 260–265 °C, and contact time at 2.5–3.5 s to limit copper dissolution from the through-hole wall and to allow flux decomposition products to escape through the solder wave. Surface-mount components on the bottom side are secured with adhesive cured at 110–130 °C for 90–120 s, and the entire board is processed within 8 hours after wave soldering to avoid moisture accumulation at the OSP-to-laminate interface. Verification uses IEC 60068-2-20 solderability testing and thermal stress conditioning per the line-card qualification plan; the terminal product is a 5G baseband line card compliant with RoHS 2011/65/EU and the electrical safety requirements of IEC 62368-1.
Fine-pitch consumer wearable mainboards carrying 0.35 mm pitch wafer-level chip-scale packages and 0201 passives impose a tighter OSP thickness ceiling because solder paste transfer and coalescence must remain repeatable after type 5 solder paste deposition through 80–100 μm stainless-steel stencils. The BASF Pad Protectant Electronic/EL Grade concentrate is diluted to 15–20 vol% in the working bath and applied at 35–40 °C for 30–50 s, producing a thinner dry film in the range of 0.15–0.25 μm on copper lands. Microetch depth is constrained to 0.8–1.2 μm because the pad-to-pad gap on this board class is below 180 μm and over-etch causes undercut of solder mask dams. Printing uses type 5 SAC305 paste per J-STD-005 with aperture area ratio not below 0.66 and post-print inspection capturing volumetric paste deposits within ±15% of nominal. Reflow is performed under nitrogen with residual oxygen below 1000 ppm at peak temperature 235–245 °C and time above liquidus 50–75 s; the inert atmosphere reduces oxidation of the exposed copper during the interval between film decomposition and solder wetting, particularly on the narrow lands of the WLCSP. Voiding in the resulting solder joints is assessed by X-ray inspection with acceptance below 25% total void area per joint, and shear force is evaluated per JEDEC JESD22-B117A on production-lot samples. The terminal product is a wearable biometric monitoring module that carries a conformal coating after test and is compliant with IEC 62368-1, RoHS 2011/65/EU, and the ionic cleanliness limit of IPC-6012 as measured by IPC-TM-650 2.3.25.
Industrial servo drive boards use heavy copper planes, often 105 μm, and are subjected to higher thermal rise during operation than consumer boards, so the electrochemical reliability of the organic pad protectant must be verified after coating rather than inferred from bath parameters alone. Coupons processed with the BASF Pad Protectant Electronic/EL Grade bath at 18–22 vol%, 38–42 °C, and 60–90 s vertical dip immersion are measured by ellipsometry against a bare-copper reference, with acceptance at 0.20–0.30 μm dry film thickness per IPC-4555. Ionic cleanliness after the coating line is evaluated by IPC-TM-650 2.3.25 using an Omegameter; the acceptance threshold is 1.56 μg/cm² NaCl equivalent, and values above this limit require an additional deionized water rinse before final drying. The table below compares the process parameter windows for vertical dip and horizontal conveyorized spray configurations used on this product class.
| Process Variable | Vertical Dip Cell | Horizontal Conveyorized Spray |
|---|---|---|
| Working bath concentration | 15–20 vol% | 18–25 vol% |
| Operating temperature | 36–40 °C | 38–42 °C |
| Contact time | 45–90 s | 25–45 s |
| Microetch depth | 1.0–1.5 μm | 1.2–1.8 μm |
| Dry film thickness | 0.20–0.30 μm | 0.25–0.35 μm |
| Ionic contamination after coating | <1.56 μg/cm² NaCl equivalent per IPC-TM-650 2.3.25 | |
The servo drive boards then proceed to mixed SMT and through-hole assembly, with selective wave soldering used for connector pins. OSP films at the upper thickness limit of 0.35 μm on heavy copper planes can reduce selective soldering wetting speed, and the selective nozzle is therefore held at 280–290 °C with nitrogen shrouding at <500 ppm residual oxygen to compensate for the higher thermal mass of the board. Solderability is verified on sacrificial coupons using J-STD-003 with dip-and-look and wetting balance methods; wetting force within 2 s at 245 °C using SAC305 is the production acceptance criterion. The terminal product is an insulated-gate bipolar transistor servo drive board rated for 480 V three-phase input, compliant with IPC-A-610 class 3, IEC 61800-5-1, and the applicable sections of RoHS 2011/65/EU.
On server motherboards that must pass in-circuit test after SMT, the pad protectant film is contacted by flying probe spring contacts with tip diameter 0.10–0.15 mm and contact force 10–30 gf per point. The organic layer is not electrically conductive in the dry state; probe penetration is required to achieve the continuity threshold of 10 Ω at 10 mA forced current specified in IPC-9252A. Boards processed with the BASF Pad Protectant Electronic/EL Grade at 20 vol%, 38 °C, and 50 s horizontal spray contact show a dry film thickness of 0.20–0.28 μm, which permits reliable probe penetration with new probe sets. In production, film thickness above 0.35 μm has been correlated with intermittent open classifications on flat SMT pads when probe tip wear reduces penetration depth; replacing probes after 200,000 contact cycles and re-verifying penetration with a calibrated reference board maintains first-pass yield above 98%. Automated optical inspection is conducted before electrical test because the transparent organic film produces only minor reflectivity shifts on copper pads at thickness below 0.30 μm, but higher thickness creates localized colour variation that can increase false call rates on 2D AOI systems. The terminal product is a dual-socket server motherboard compliant with IPC-A-600 class 3, IPC-9252A, and RoHS 2011/65/EU, with the pad protectant film accepted only when the test-probe contact resistance criterion is met on 100% of nets.
Boards with the BASF Pad Protectant Electronic/EL Grade film are normally sealed in moisture-barrier packaging with desiccant and a humidity indicator card per IPC-1601A storage guidance. At 20–25 °C and 40–60% RH, solderability remains acceptable for at least 6 months; at 30 °C and 70% RH, copper oxidation through micro-defects in the organic film has been observed within 90 days on production lots placed in tropical warehouse conditions. If boards exceed these limits, the organic film cannot be regenerated by baking alone because the failure mechanism is not moisture absorption but underlying copper oxide growth at film discontinuities. Reconditioning begins with stripping of the degraded film in a 5 vol% sulfuric acid and 2 wt% sodium persulfate solution at 30 °C for 60 s, followed by cascading deionized water rinses, a fresh microetch removing 1.0–1.5 μm of copper, and re-coating in the protectant bath at 20 vol%, 38–42 °C, and 50–70 s. Solderability after reconditioning is verified on coupons with J-STD-003 wetting balance using SAC305 at 245 °C; acceptance requires wetting initiation within 2 s and complete wetting within 5 s. The terminal product is a 5G base station transceiver board subjected to this reconditioning step only when the previous storage history is outside the documented barrier-packaging window, and the final assembly remains compliant with IEC 60068-2-20, IPC-A-610 class 3, and RoHS 2011/65/EU.
Competitive PCB Pad Protectant (BASF Pad Protectant) Electronic/EL Grade prices that fit your budget—flexible terms and customized quotes for every order.
For samples, pricing, or more information, please contact us at +8615365186327 or mail to admin@ascent-chem.com.
We will respond to you as soon as possible.
Tel: +8615365186327
Email: admin@ascent-chem.com
Flexible payment, competitive price, premium service - Inquire now!
PCB Pad Protectant (BASF Pad Protectant) Electronic/EL Grade is supplied as a temporary, UV-curable peelable mask for selective protection of printed circuit board pads, edge fingers, and test points during wave soldering, selective soldering, hot air solder leveling, and conformal coating operations. The Electronic/EL designation identifies a low-ionic-leachable formulation distinct from industrial peelable latex and general-purpose UV masks. Total halide release after cured film removal is specified below 10 ppm chloride equivalent when extracted in 75 °C deionized water for 24 h according to IPC-TM-650 2.3.25. The product is a one-part material; no solvent thinning is required for standard screen printing at ambient temperature. Two application-rheology forms are used in assembly floors: a high-viscosity thixotropic paste for stainless-steel mesh and stencil printing, and a lower-viscosity form for air-assisted spray coating of pad fields with high component density. Batch certificates govern final viscosity, cure dose, and extractable residue values.
On production lines, the material is transferred through 100–120 mesh stainless-steel screens or 150 µm laser-cut stencils. The paste exhibits shear-thinning behavior; apparent viscosity decreases from typical low-shear values of 12,000–16,000 mPa·s at 10 rpm on a Brookfield RV spindle 7 to below 2,500 mPa·s at 100 s⁻¹. This permits aperture filling without post-print slump on 0.4 mm pitch QFP pad lands. Snap-off is maintained at 0.6–1.0 mm, print speed between 60 mm/s and 120 mm/s, and squeegee durometer at 70–75 Shore A. Squeegee pressure is held between 2.5 N/cm² and 5.0 N/cm². Under shop lighting filtered below 420 nm, open stencil life exceeds 16 h, and viscosity drift measured at 8 h under 30 °C/60% RH remains below 10% of the initial value. High-shear dispersion is not required; entrapped air from pneumatic press cartridges is removed by slow mixing under 25 kPa vacuum for 5 min before print start.
For air-assisted spray application of pad fields larger than 25 mm × 25 mm, the low-viscosity Electronic/EL Grade is adjusted to 350–700 mPa·s at 25 °C with a propylene glycol methyl ether acetate thinner. Spray equipment typically uses a 0.8 mm nozzle, 2.5 bar air pressure, 30 cm working distance, and 45° spray angle. Dry film build greater than 60 µm after a single pass is not recommended because solvent entrapment lowers cohesive strength. Sprayed films are flashed at 23 °C for 15–20 min before UV cure to remove retained solvent; otherwise, rapid UV skinning traps solvent and causes blisters during wave contact at 268 °C. The spray form is not designed for stencil printing because low viscosity causes bleed under the stencil on separation gaps above 10 µm.
UV curing proceeds via radical acrylate polymerization. In air, oxygen competes with crosslink formation at the film surface, producing a tacky layer if the applied UVA dose is below the oxygen-inhibition threshold. The recommended surface dose is 2.0–2.5 J/cm² at 365 nm; through-cure of a 0.15 mm printed film may require 4.0 J/cm² when pigmentation or shadowed pad edges reduce photon penetration. A 120 W/cm mercury arc lamp operating at 8 m/min conveyor speed and 25 mm focal distance delivers approximately 1.8 J/cm² per pass; therefore, two passes are usually specified for tack-free edge definition. For pads shadowed by connectors with 0.5 mm standoff, the local dose may fall below 0.7 J/cm². In such cases, the board is rotated 90° between passes or post-baked at 80 °C for 15 min to complete surface conversion. Nitrogen inerting to 1,000 ppm O₂ reduces the required dose by approximately 30% and is used in high-volume cells where throughput exceeds 4.0 m/min.
Compared with solvent-borne latex peelable masks, the Electronic/EL Grade leaves lower halide and sulfate residues after peeling; this is decisive on no-clean assemblies where flux activators are not removed. General-purpose latex systems may contain acetic acid or ammonia that can attack immersion silver and exposed copper during thermal cycles. Thermosetting epoxy masks require a thermal cure that can exceed 120 °C for 30 min; the BASF pad protectant cures at ambient equipment temperature and avoids thermal distortion of thin cores below 0.4 mm. The peelable UV film also leaves no silica filler residue on gold contacts, unlike some filled rubber masks. The Electronic/EL Grade is formulated with acid value below 10 mg KOH/g and amine value below 5 mg KOH/g, reducing interaction with organic acid no-clean fluxes and limiting pH shift on remaining moisture films.
| Parameter | Method | Typical specification |
|---|---|---|
| Ionic extractable residue after cured film removal | IPC-TM-650 2.3.25 | < 1.0 µg NaCl eq/cm² |
| Surface insulation resistance after removal | IPC-TM-650 2.6.3.7 | > 1.0 × 10⁸ Ω at 85 °C/85% RH/100 V DC |
| Flammability | UL 94 | V-0 at 0.15 mm on FR-4 |
| RoHS restriction | 2011/65/EU recast | Pb, Hg, Cr(VI), PBB, PBDE < 0.1 wt%; Cd < 0.01 wt% |
| REACH SVHC | Regulation (EC) No 1907/2006 | Below 0.1 wt% per article |
Under selective soldering with aggressive no-clean fluxes, the cured mask remains in place through preheat zones of 105–120 °C for 45–90 s and survives contact with a 268 °C SAC305 wave for 2.5–4.0 s. The film does not delaminate from ENIG, OSP, or bare copper pad metallurgies when the board surface is free of silicone-based residues. Removal after soldering is performed by hand peel at 45° to the pad plane, using a polypropylene tab. Measured peel force on ENIG is typically 0.02–0.05 N/mm and on bare copper 0.03–0.08 N/mm under ASTM D3330. The mask is removed as a continuous strip. Fragmentation at 0.4 mm pitch pad interspaces indicates incomplete through-cure or excessive print thickness below 50 µm; the minimum recommended dry film is 75 µm to maintain cohesive failure during peel.
Storage in opaque containers at 5–25 °C preserves the material for 12 months from the date of manufacture when the container remains sealed. Exposure to direct sunlight or shop UV lamps causes premature gelation. At floor-side dispensing, cartridges should be warmed to 20–25 °C for 4 h before use to stabilize flow. If the paste is stored at 5 °C, viscosity may rise by 20–30% but returns to specification after controlled warm-up and low-shear mixing. Repeated freeze-thaw cycles are not recommended; storage below 0 °C can destabilize the thixotropic network and lead to phase separation. The Electronic/EL Grade is not formulated for high-temperature bake storage above 40 °C, because oligomer advancement may increase viscosity and reduce cure response.
On assemblies with mixed ENIG and OSP pads, the mask adheres sufficiently to OSP to survive top-side reflow but releases without lifting the OSP film if peel force is kept below 0.05 N/mm and peel angle is maintained below 30°. If film removal exposes a visible white residue on OSP, the residue is typically abietic acid from flux interaction rather than mask residue; extraction under IPC-TM-650 2.3.25 should be repeated after an isopropanol rinse. The Electronic/EL Grade is also compatible with automated optical inspection systems because its blue-green color provides contrast against gold, copper, and tin-pad surfaces under 470 nm LED illumination. After peel, no additional plasma cleaning is required for pads protected by the EL grade, provided that the film was cured above the oxygen-inhibition threshold and removed immediately after soldering.
Where the mask is used under conformal coating masking on flexible polyimide substrates, low outgassing prevents contamination of 1 µm line-space test traces. Cured films exposed to 125 °C for 24 h under vacuum exhibit collected volatile condensable materials below 0.1% of film mass when measured by ASTM E595-15. The Electronic/EL Grade is not specified for space-grade outgassing unless the batch certificate includes an ASTM E595 appendix; published data for this specific configuration is limited. For standard commercial aerospace assemblies, users typically verify cleanliness through in-circuit test after mask removal because the residual silicate-free acrylic network resists forming conductive particulate during peel.
Operational boundaries include incompatibility with polyimide pad sites previously contaminated with silicone mold-release. Silicone lowers peel adhesion and leads to film lifting during wave contact. The material is not intended for continuous immersion in organic acid fluxes longer than 8 h at 60 °C; such service may plasticize the film and reduce tensile strength below 1 MPa. It is not classified as a permanent barrier or conformal coating replacement. Combustion by-products of the cured acrylate film may include carbon dioxide, carbon monoxide, and low-molecular-weight acrylates if incinerated below 800 °C; standard electronics waste treatment under RoHS does not require special disposal classification, but local regulations govern incineration. Published data for continuous immersion service is limited; process validation should include post-peel contact resistance measurement on a representative mixed-metal pad array.
