Fengfan CAS 17636-10-1 ST-001 Polyalkylene Glycol Monobutyl ether Copper plating

Product Overview

ST-001 is a polyalkylene glycol monobutyl ether - an alkyl-capped EO/PO block polyether supplied as a colorless to yellowish liquid. Its job in a copper plating line is wetting: it changes how the electrolyte behaves at the boundary with the workpiece, so the solution reaches recessed surfaces, drilled holes and fine features instead of only the flat areas facing the anode.

The molecule is an ethylene oxide / propylene oxide block with an alkyl cap at one end. That structure is what separates it from a general-purpose surfactant. The polyether backbone stays compatible with the strongly acidic, high-sulfate electrolyte of an acid copper plating bath, and the capped end holds the molecule at the interface where it does its work rather than letting it drift in the bulk of the solution. Formulators use it to bring wetting, leveling and dispersion into one additive instead of stacking three.

The same polyether lubricates and carries oil, so this product is bought by two groups: plating engineers building or topping up an acid copper bath, and formulators who need a carrier for lubricating oils and cutting fluids. Both work from the same drum and the same batch record. The physical data on this product describes the product as supplied, not a diluted working solution.

Specifications

Performance in the Bath

• Wetting at the interface. As a surface active agent, this polyether collects at the boundary between electrolyte and cathode and lowers surface tension there. Holes, slots and recessed areas fill with solution instead of trapping air, which is the difference between a clean plated barrel and a void.
• Leveling support. It does not brighten on its own; it makes the brightener and leveler work evenly. By keeping the additive film uniform across the surface, it helps the deposit build at a similar rate on high-current-density edges and low-current-density centres.
• Holding the package where the deposit forms. The capped end of the molecule keeps the additive at the surface rather than in the bulk of the plating bath, so the other organic components arrive where the metal is being laid down.
• Dispersion. Organic additives in a working bath tend to cluster. This product keeps them dispersed, which is what prevents streaking and patchy results when a panel runs a long cycle.
• A liquid that meters cleanly. Viscosity is specified at 25 °C and the product stays mobile at shop temperature, so it can be pre-diluted and weighed or pumped without heating - useful when several copper plating chemicals go into the same bath on the same shift.
• One chemistry, two uses. The same grade serves the metal plating process on the plating side and the lubricant formulator on the industrial side, so a distributor can hold a single drum for both.

Applications

On a printed circuit board line the wetting component decides whether a plated-through hole fills cleanly. Panel plating, pattern plating and via filling all run in a copper plating bath, and the solution has to reach the barrel of a narrow drilled hole where no pump can push it, then leave the copper surface clean enough for the next step. Board shops usually trim the wetting agent last, after the brightener and leveler are set.

Electronic components and connectors follow the same logic at a smaller scale. Where a part has blind recesses, stamped pockets or a plated thread, wetting is what stops a dry patch turning into a skip. The plating step on a connector shell is short, so the additive has to act within seconds rather than over a long immersion. The same requirement holds in any metal plating process that deposits copper from an acid electrolyte, including general hardware and decorative work.

Away from the copper plating line, the same product works as a carrier for lubricating oils and cutting fluids. A butyl-capped EO/PO block is a non-ionic polyether, so it blends into an oil-based formulation without introducing an ionic component, and it helps the oil spread evenly across the tool and the workpiece.

Additive Compatibility

• With chloride. Chloride is the standard activator in an acid copper plating bath and works on a different part of the mechanism than the wetting agent. Set chloride first and trim the wetting agent after, otherwise the two adjustments mask each other on the panel.
• With brighteners and levelers. Sulfur-type brighteners and nitrogen-type levelers set gloss and grain refinement; this product supplies none of that. Treat it as the wetting layer beneath them and adjust it only once the brightener system is stable.
• With other polyethers. Polyethylene glycol and similar polyethers already provide some wetting. If the bath runs one, add this product in steps and check a Hull cell panel between additions rather than substituting drum for drum.
• Order of addition. Pre-dilute, add under circulation and let the tank mix before the next panel. Tipping neat product into a still tank creates a local over-concentration that shows up as roughness and gets blamed on the wrong additive.
• When you change suppliers. Two drums of copper plating chemicals carrying the same description are not automatically interchangeable. Compare the viscosity range and specific gravity of the incoming drum with the outgoing one, and confirm the starting addition with our technical contact, because the published data does not include a recommended dose.
• What it will not fix. If panels burn at the high-current-density edge, the cause is usually current density or chloride before it is wetting. A surface active agent changes how the solution wets the surface; it does not change how much metal the rectifier delivers.

Bath Introduction and Control

1. Record what the bath is running now: current wetting agent and its level, chloride, temperature and the last Hull cell panel. That is the baseline you judge the change against.
2. Confirm the starting addition with our technical contact. We do not publish a single recommended dose, because it depends on the make-up of the copper plating bath, drag-out and which other polyethers are already present.
3. Pre-dilute the product in a pail of bath or demineralised water. Never pour neat product into a still tank, or the first panel afterwards will show roughness that has nothing to do with the grade.
4. Add slowly at the circulation point with the plating bath moving, then let the tank mix fully before running the next panel.
5. Run a Hull cell panel across the working current density range and compare it with the baseline. Look for wetting failures in the low-current-density area and for haze or roughness at the high-current-density edge.
6. Log the addition against the drum batch number, reseal the drum and keep it in a cool, dry place. When the bath needs topping up, add in the same proportion and re-check with a panel instead of adding on a hunch.

Ordering and Delivery

Technical Support & Model Matching

Choosing the right match is where most sourcing decisions stall. As a trading supplier, we keep one point of contact from first enquiry to after-sales: tell us what you are making and the conditions you work under, and we shortlist the closest matches from our supplier network, compare specifications and arrange samples before you commit to a bulk order. If something does not behave as expected, we work with the supplying partner on the cause and a practical fix, and stay with the case until it is settled. Email, WeChat or WhatsApp enquiries get a reply within 24 hours.

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