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Ted Mooney, P.E. RET
Pine Beach, NJ
The authoritative public forum
for Metal Finishing since 1989
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Best Pulse Plating Settings for PCB/PWB?
Q. Pulse plating for PCB?
Any data about specifically complex wave form and its effects on through-hole and microvia plating.
- Singapore
October 25, 2021
⇩ Related postings, oldest first ⇩
Q. I want to reduce the "non-plating" problem caused by air or hydrogen bubbles in nickel plating bath for PCB.
My Question is:
1. Is ultrasonic effective to separate bubble from the metal surface?
2. Can it affect any property of plated metal layer?
Thank you,
- Osan, Korea
2001
A. I don't think you want ultrasonics (it actually creates bubbles). Try adding a surfactant to the bath; you can probably purchase it from your nickel bath supplier.
James Totter, CEF
- Tallahassee, Florida
2001
A. The answer is yes to both. The bubble gets broken down by the ultrasonic and increases plating speed substantially. The coating is much harder (I haven't measured it so I can't commit).
This may aggravate the problem actually for your PCBs with faster edge build up on your holes. I have used Reverse pulse plating to great advantage and I would say that is the way to go.
Khozem Vahaanwala
Saify Ind
Bengaluru, Karnataka, India
2001
Special Brighteners for Periodic Reverse Pulse Plating?
Q. I'm doing small PCB shop and going to try for Periodic Reverse Pulse Plating to help more built up hole wall thickness, any ones know that can I use conventional brighteners ? and any difference with PPR brighteners ? ( Copper Plate )
Suvatn S.- Bangkok, Thailand
2003
A. The additives often used in conventional copper plating are not always suited to pulse plating technologies. I would suggest you talk with your chemical supplier to ensure the additives will still function correctly. Try Macdermid, they have some expertise in this field.
Trevor Crichton
R&D practical scientist
Chesham, Bucks, UK
2003
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Ed. note: We appreciate Trevor's advice from 2003 that Macdermid may have some expertise in this field, but many years later we no longer suggest brands & sources on this site ( huh? why?).
Pulse Reverse Copper Plating
We are a manufacturer of brass hardware and are sometimes faced with the problem of pitting in brass castings, to which we give a heavy coat of acid copper plating (.50 hrs to 2.30 hrs) depending upon the depth and the size of the pit, after plating the part is polished flat, so the excess copper plating is removed while filling the pits.
This works fine but is time consuming, I was wondering if it was possible to use PULSE-REVERSE rectifier, which changes the polarity of the charge according to the predefined cycle, for instance, in a
20 second cycle, the rectifier gives 15 seconds of forward charge while in the second step gives a reverse current of 5 seconds, thus enabling to fill in the valleys without overbuilding the peaks.
I believe this is a popular technology in printed circuit boarding plating, but can it work on brass hardware to fill the pits.
Looking forward to your valued feedbacks.
plant operator - Moradabad, UP, India
March 19, 2010
A. Dear Jamal, you have not explained the pits in detailed , if they are microscopic the process followed is justified, if the pits are heavy then I would suggest either brazing and or soldering with pure tin on flash copper plated surface
good luck
- BELGAUM, KARNATAKA, India
May 13, 2010
A. Dear Mr Jamal,
Pulse reverse etches away the plated copper back into the solution and you need to have supporting chemistry to be able to keep the plating bath stable. Its a good idea to try it out but do use the PCB range of Acid copper additives instead of basic salts when you use pulse reverse.
Good luck and let us know how it works out.
Khozem Vahaanwala
Saify Ind
Bengaluru, Karnataka, India
May 16, 2010
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