Formulas for Electroless Copper Plating Baths

A. I would suggest consulting the "Metal Finishing Guidebook and Directory".

A. Hi, cousin Murat. If possible, could you please preface your question with who you are and why you want to know, so that people will be in a better position to understand & answer the question? To my knowledge virtually all electroless copper used in the U.S.A. is proprietary (trade secret or covered by patent) rather than made to a publicly available formula. If I'm wrong, I hope another reader will correct me.

Q. Sorry, I'm working with chrome plating on ABS plastics in Turkey. I'm using palladium/electroless nickel system. But it's very expensive. My EN solution contains nickel chloride, trisodium citrate, ammonium chloride, sodium hypophosphite and lead acetate. Can I work with silver nitrate/borane system with this formulation.

Best Regards...

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A. Thanks, Murat. I'm familiar with the use of two-part silvering solutions to metallize things like the masters for vinyl record stampers where outstanding adhesion to the substrate is not required. But I am not personally familiar with using this process in lieu of the palladium chloride approach for a decorative plating-on-plastics application, where excellent adhesion is probably a requirement. But letter number 10887 discusses that prospect in some detail. Good luck.

A. Sodium carbonate may act as buffering agent at pH of solution; for example, in alkaline electroless nickel, NH4Cl can buffer the solution. NaCO3 is mixture of weak acid and strong alkali.the pH of it about 10.

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A. I'm not sure what the function of sodium carbonate in a tartrate electroless copper bath is (maybe a buffer?), but I will tell you this: Tartrate baths are used for ease of waste treatment; the tartrate does not chelate as strongly as EDTA or quadrol. In this type of bath the tartrate (Rochelle salt) is the complexing agent, copper sulphate ⇦ this on eBay or Amazon [affil links] is the metal source, formaldehyde is the reducing agent, and sodium hydroxide is a reactant.

A. Hi Don. To my knowledge there are no commercial quadrol or EDTA-based copper plating baths. I think James' comment implies that we want to avoid those chemicals where possible because they make proper waste treatment and disposal too difficult.

Regards,

A. I am a Lab Technician and deal with electroless copper quite often, The formulation of the bath consists of Sodium Hydroxide, Formaldehyde, EDTA, SR, and electroless copper of course ... The levels of these chemicals are maintained using an "s" controller, which performs constant titrations of the components, and is verified by lab analysis every 4 hrs to ensure accuracy; except the electroless copper is measured in millivolts, which are determined by how much light can pass through the solution, when a sample is passed through a UV vis spectrometer. It is replenished by adding a 3-part chemistry "a, r and c".

A. Hi Kevin

Research papers do not indicate a fully developed stable process. They are mostly written to support an academic study and there is rarely any expectation that they will see the light of day again. (The same goes for published patents)

In order for an electroless process to work, it must be just marginally stable. Too stable and there is no deposit; too unstable and it "falls apart" To get the balance right and controllable major suppliers have invested large sums and much expertise. They are unlikely to give away the secrets of their success lightly.

Many thousand litres of commercial electroless copper are in use every day. If your interest is purely academic, I wish you luck with years of fascinating research before you. But if you are looking for a viable production process, I urge you to contact any of the major suppliers. They will not only supply a working process but also teach you how to operate it - and probably at a lower cost than buying the chemicals.

A. If you have the time, you could research the formulae in the patent literature and spend tens of thousands of hours perfecting your formulae. Or, if you don't, you could buy a commercially available bath developed by companies like Macdermid, Enthone, Atotech, and many others, who have already done this for you.

A. Hi Alex

If by student, Loughborough you mean Loughborough University, I suggest that you take yourself to the Department of Materials Engineering where you will find Emeritus Professor David Gabe who will give you infinitely more and better advice than even this illustrious website.