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Quantity of dross and type of flux

Mohammed Saad

#2471

Quantity of dross and type of flux | 14 November, 2000

Hi, I need some information about the relation between the type of flux used in wave soldering and the quantity of dross produced.

Thank you in advance for your help

Mohammed

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#2472

Re: Quantity of dross and type of flux | 14 November, 2000

I'd love to get to the point that I could discuss the impact of flux on dross formation. Until then, I fight with proper solder pot temperature, maintaining enough pump speed, and solder contaminants.

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Vince Whipple

#2473

Re: Quantity of dross and type of flux | 21 November, 2000

Mohammed, The first suggested place to start with your question would probably be with your flux Mfr. Push them!

The quantity of dross is effected by several factors: The higher your solder pot temp., the higher your dross level... but don't go too low.. you may compromise solder results (top-side fill, bridging, etc). A good place i try to stay is in the range of 480 to 490F.

The chip wave exposes gobbs of fresh solder. this will also increase the levels.

Typically (with NoCleans) the higher the quantity of flux, the higher the dross level.

There are many ways to address dross levels. First, identify why they are a concern to your operation and what levels are acceptable.

Is the question raised because Operators are not removing the dross in a timely fassion and it changes the pumped up level? When was the last time the pump was pulled to remove the "black stuff"? Is the dross compromising the joints?

There are also several methods for handling dross after it is created... DeDrossing agents, Solder recovery systems.

Why is dross the problem? then hit it.

Have a fun Turkey day, catch you next week.

vwhipple@sono-tek.com

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