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Black residue at end of wave soldering

cpgoh

#4639

Black residue at end of wave soldering | 16 March, 2000

Hi, I would appreciate some help here.. I am black residue with my wave soldering provess with my Electrovert machine sometimes, they are dotted all over the board ! I am also using no clean flux through an externel spry fluxer unit.. thanks Darren

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#4640

Re: Black residue at end of wave soldering | 17 March, 2000

Darren: Do you know what these residues are ? How clean is your solderbath ? How often during a day do you clean it ? My first impression is that you deal with oxides.

M2C

Wolfgang

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sosina_outry

#4641

Re: Black residue at end of wave soldering | 17 March, 2000

Daren: suggestion from a friend of mine 1. Is residue on the top or bottom of the board? If on the bottom, then you might need to do solder dedross.

if on the top, you might need to check 1. after spray flux, check for any excess flux on the top of the board..may be you start your fluxer too early. 2. check the preheat with chip and lamda for any color change 3. Then run normal to check chip and lamda wave.

hope it can help you. sin

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cpgoh

#4642

Re: Black residue at end of wave soldering | 30 March, 2000

HI all, thanks for the advise.. Electrovert is being used from 7am to 7pm and we do dedross from the surface of the solder bath during lunch time around 12nn. Break Time we just sweep them to the side.. Every two week, we do the solder bath maintenance, paying attention to the head.. chip and lambda.. and the pump the dirty patch is under the board and the solder bath sample had been tested by the vendor to be OK.

I do not know if there is any problem with the way we are servicing.. any suggestion ? the "harden" dirt in the solder pot or at pump are ususally "knock" out while cleaning.. is that thorough enough..?

the dirty patch appear seems to be a bit powdery on top of stickiness

thank you the help so far..

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#4643

Re: Black residue at end of wave soldering | 30 March, 2000

1)>> the dirty patch appear seems to be a bit powdery on top of stickiness > the "harden" dirt in the solder pot or at pump are ususally "knock" out while cleaning.. is that thorough enough..? Assuming that 1) is true it might not be thorough enough. Once you get dross in your pot it�s hard to get it out again, normally you have to replace the whole solder content of the pot and clean every bit of a corner thoroughly. Solder sample tests usually check for different metall contents and are not looking for dross particles. Did you check with service people from Electrovert ?

That�s my guess

Wolfgang

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cpgoh

#4644

Re: Black residue at end of wave soldering | 3 April, 2000

I ever thot of changing the whole solder pot altogether but then it prove to be a costly measures.. If looking at the source of the problem, it might be mainly due to the way that the machine had been maintain... Anyone care to share how they are performing the service maintenance of the Electrovert..? I have contacted the Electrovert agent but their advise are limited..

I would appreciate if someone could help to share how they attempt to clean the solder dross and residue from the pump, the solder pot wall lining and the nozzle.. any good way to ensure that the solder pot is "very clean" ?

Is there any chemical which can just "dissolve" the dross accumulation when doing maintenance..

thank you.

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#4645

Re: Black residue at end of wave soldering | 4 April, 2000

Sorry to hear that Electrovert isn�t much help in your situation but the manufacturer of a system should be the first source of information on the equipment regarding preventive maintenance and troubleshooting. You should try to get in touch with their service departement for advice, training and cost

Good luck

Wolfgang

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D.J.

#4646

Re: Black residue at end of wave soldering | 27 April, 2000

Are you also getting voids? Could be that the solder mask on the boards is not completely cured. This will cause liquid solder mask to out-gas from under the cured skin of mask when you contact the solder wave. The mask essentially boils. The result is solder skips and residue.

Can you scratch off the residue? If not, take a solder iron to it and see if it goes away. That would be a dead giveaway>

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