Printed Circuit Board Assembly & PCB Design SMT Electronics Assembly Manufacturing Forum

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


water soluble solder mask

mikeh

#8984

water soluble solder mask | 13 October, 1999

Hi,

I am currently using a peelable mask prior to wave soldering and have started exploring water soluble/washable masks. The mask will be used with water based and alcohol based flux. Are there any compatability issues to concider and how will this affect a closed loop water wash system?

Thanks,

Mikeh

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#8985

Re: water soluble solder mask | 13 October, 1999

Mikeh: You can't let that stuff get to your carbon bed. Literally, you can watch your bed die. The clay coats the carbon, entombing it.

I've heard talk of using a RO filter as a front-end buffer to the recycling system, but know of no one who has (convinced their management to) use such a filter.

So, tell me about your current process: vinyl/latex, print/dispense, remove before/after cleaning, ammonium hydroxide is/isn't a concern, cure in air/oven?

My2�

Dave F

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mikeh

#8986

Re: water soluble solder mask | 13 October, 1999

Dave F,

We are currently using a latex based ambient/thermal cure material that is applied by hand or automated dispensing equipment. Printing is an option for us, but we have not had much luck with this particular material. The mask is peeled off after wave soldering. Ammonia is a concern.

Mikeh

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Brian W.

#8987

Re: water soluble solder mask | 13 October, 1999

There is a company in Florida that was using water soluble solder mask with their wash system. The gentleman to call there is Lynn Hurt, their Sr. Staff Engineer. Switchboard number is 352-799-6520.

Brian

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Graham Naisbitt

#8988

Re: water soluble solder mask | 14 October, 1999

The latex should not influence your closed-loop filtration - unless of course it falls off during cleaning.

The issue would be with water soluble materials. As Dave (hi Dave) said, the clay based version of these will clog/blind/knacker your carbon bed.

The other type is based on salt, so it would be OK for your carbon bed but will kill your resin beds real fast.

General recommendation is to send your pre-wash to drain - and close-loop the rest. This way the bulk of the solubalised mask would be taken away from the filters - but you may then have to revisit your drainage system.

Regards, Graham AKA GooRoo.

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Dennis O'Donnell

#8989

Re: water soluble solder mask | 14 October, 1999

Water soluble masks are great in my book. After having used the latex type, I found that the water soluble will save a lot of time.

I dont't use a closed loop system, but I do have a filter on my discharge line. I have not experienced any filter clogging problems to date.

I have found that Kester and Tech Spray make a good product. Tech Spray however is half the price.

go to www.pcb-repair.com for assembly solutions.

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