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How to remove bubbles formed in the plating sump?

2005

We observed that there are a lot of tiny bubbles in our electro Cu plating sumps. It may come from the pumping and overflowing of the plating solution. There's a 10um filter connected to the inlet pipeline to plating section. However, bubbles are still able to reach the plating section and create "clean pits" in the copper finishing.

It looks hard to suppress bubbles generation. So we're working on how to remove the bubbles to stop it from going back to the plating section.

1. Will selecting a finer filter help in reducing the amount of bubbles being pumped up?
2. Any special filter/mechanism that's able to remove bubbles without generating more of them?

Thanks.

Ang Tiong Tuck
Electronics - Singapore

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2005

Hi Ang !

Re your bubbles, ah, I don't think that a finer filter will help at all.

But consider reducing the surface tension ... go and add some TSP (trisodium phosphate ⇦ this on eBay or Amazon [affil links] ) or a similar wetting agent.

If that works, let us know, please.

Freeman Newton [deceased]
(It is our sad duty to advise that Freeman passed away
April 21, 2012. R.I.P. old friend).

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2005

Thanks for suggestion Freeman.
But I'm afraid adding a wetting agent may require a full re-qualification. However, we'll surely look into this.

The bubbles seem to be coming from overflowing and splashing of the plating solution. We're hoping it can be reduced by changing the filter or its design. Keep my finger crossed.

Ang Tiong Tuck
- Singapore

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2005

Hi Ang !

I got to thinking (v. poor English) isn't there in your business a material, ie. liquid? called ANTI FROTHING AGENT, but I'd hazard a bet that it contains TSP !

Just a thought.

Again, I sure don't think that a finer filter will help ...
all you'd get would be finer bubbles, methinks. Anyhow, fine filters plug up easily so I'd use a coarse prefilter ahead, wouldn't you?

Nice clean city Singapore ... lovely bird zoo, too ...

Freeman Newton [deceased]
(It is our sad duty to advise that Freeman passed away
April 21, 2012. R.I.P. old friend).