After welding, the PCB becomes damaged

[rmendes]

Hi, sorry for beginner questions.
was the second time this happened to me, about two months after soldering the PCB begins deteriorate.


why this happened and what I'm doing wrong?

I put flux FP3030 to desolder, and after solder

Thanks

[suicidaleggroll]

Sounds like you're using the wrong flux (maybe you're using plumbing flux instead of electrical?).  What is FP3030?  I've never heard of it and can't find anything on Google, do you have a link?  Are you cleaning the flux off of the board when you're done or just leaving it?  If you're cleaning it, what are you using to clean?

[fable]

Temperature is set to high.Wath kind of tool you are using?

[grumpydoc]

Sounds like you're using the wrong flux (maybe you're using plumbing flux instead of electrical?).  What is FP3030?  I've never heard of it and can't find anything on Google, do you have a link?  Are you cleaning the flux off of the board when you're done or just leaving it?  If you're cleaning it, what are you using to clean?

Search for Castolin FP3030 but all the hits are Spanish or Portugese.

However as one bit I could get google to translate says "Applications Gel Bronze, brass, copper and steel" I would assume that it is an acid flux not designed for electronics work.

It certainly looks that way given what it has done to the PCB.   

[james_s]

Yeah I'd bet money that's the result of acid core plumbing or brazing flux.

For electronics you should use *only* rosin core electronics solder.

[Audioguru]

I think he is using a blow torch instead of a temperature-controlled soldering iron.
Oh, the title says he is welding instead of soldering.

[Paul Moir]

"Soldering" "Welding" and "Brazing" don't translate well.  Even in English "Soldering" and "Brazing" only used conventionally.
Don'tcha watch "How It's Made"? 

[SkyMaster]

Oh, the title says he is welding instead of soldering.

rmendes, the OP is from Portugal. English his not is first language.

I do not speak Portuguese, but I speak French, and in French "soldering" and "welding" both translate to the same word (soudage). I can assume it could be the same situation in Portuguese.

Also, this is the Beginners section of the forum, so everybody deserve a second, a third and a fourth chance.

 

[james_s]

I see a lot of Chinglish documentation that refers to FETs as "tubes" so this doesn't surprise me.

[tpowell1830]

@rmendes

To answer your question, the flux is not the correct flux to use on electronic boards or any type of electrical soldering. Also, if you are using an acid core flux in your solder, then this could happen as well.

The flux type to use in the solder and for priming is rosin core sometimes spelled 'resin'. There are many types of rosin primers and you may want to try several to find one of your favor. However, make sure that your solder is rosin core solder.

From the pictures it appears that you used acid core solder and/or acid based primer flux. This explains the condition of your board as acid is very destructive to electronic boards.

I hope this makes sense to you and welcome to the forum.

[rmendes]

Hi thanks very much, for your answers, yes I'm Portuguese. and I'm also suspect it's because of the flux

[tooki]

The flux type to use in the solder and for priming is rosin core sometimes spelled 'resin'.

Resin and rosin are not alternate spellings - they're different things.

[Nusa]

The flux type to use in the solder and for priming is rosin core sometimes spelled 'resin'.

Resin and rosin are not alternate spellings - they're different things.

Perhaps you're thinking of a non-English definition? They can mean the same thing, by actual dictionary defintion:
http://www.dictionary.com/browse/rosin
https://en.oxforddictionaries.com/definition/rosin
http://www.yourdictionary.com/rosin

[helius]

They are different things that are only synonyms under very restrictive interpretations.

Rosin is the solid component of pine tar, exclusive of liquids such as turpentine. There are many kinds of pine, so there are many different rosins, but they are all from pine trees. Rosin is also called "colophony". As a flux, it is dissolved in a solvent, usually alcohol but could also be a light hydrocarbon like hexane, or even ethyl acetate. Other modifiers like glycerol can also be added.

Resin is a very broad term, which encompasses both plant saps (liquid like rubber or solid like amber), insect secretions, and man-made chemicals. Their common property is the ability to form hard plastics by condensation reactions. As a flux, resin refers to chemicals derived from rosin with specific modifications. For instance, a single compound is extracted from the rosin, and then hydrogenated or reacted with another chemical. The effect is to customize the physical properties, like activation temperature, form of residues, and wetting.

[Cubdriver]

That looks to me to be corrosion from an acid flux, and as bad as it looks I'd suspect it's a brazing or plumbing type flux rather than a water soluble that hasn't been properly cleaned off.

The fact that it happens over time also makes it sound flux and corrosion related, rather than being caused by heat.

Try to get some electronic grade rosin core solder and give that a shot - I bet your results will be much better and longer lasting.

-Pat

[tooki]

The flux type to use in the solder and for priming is rosin core sometimes spelled 'resin'.

Resin and rosin are not alternate spellings - they're different things.

Perhaps you're thinking of a non-English definition? They can mean the same thing, by actual dictionary defintion:
http://www.dictionary.com/browse/rosin
https://en.oxforddictionaries.com/definition/rosin
http://www.yourdictionary.com/rosin

English is my native language, and we are discussing the English word "rosin". Other languages tend to use a variant of the word "colophony".

You only looked up "rosin". Now go look up "resin" and you'll find very different definitions. Or read helius's reply, which summarizes it beautifully.

All rosin is a type of resin, but not all resin is rosin.

[dmills]

I see a lot of Chinglish documentation that refers to FETs as "tubes" so this doesn't surprise me.

Well a valve (US Tube) is colloquially referred to around here as a "vacuum fet", and they even do dual and triple gate versions... So I can sort of see the logic.

Regards, Dan.

[Richard Head]

Isn't "colophony" that detox procedure that's done with a hosepipe? Maybe I'm getting my colons muddled up?

[matkar]

Here is my experience with different fluxes I used in the past.
When I started I had a flux called Cinol which is produced in my country. It is greasy and looks like fluxes from ebay but it smells much worse. In general it works well for soldering wires. On one occasion years back I used it to solder a prototype since my rosin went out. It was a TH job, a signaling board with LEDs and ULN2003s. The problem I experienced was all the LEDs started flickering sporadically when power was applied. After cleaning the board in very hot water with detergent (cleaning with isopropanol didn't help to remove the grease) The board started functioning normally. Later I have heard other people had similar experience with Cinol. I never used that flux for board work ever again.
A few years back I bought a bottle of flux that is used in PCB manufacturing industry. They use it to tin the boards at the end of process (HASL). It worked very well but smells awfully. I stopped using it after I discovered it had some similar qualities as OP's flux does. The board became corroded after some time. And that happened even after cleaning the board in isopropanol. It was impossible to remove all the flux from beneath the chips so every board where I used it was a ticking bomb.
I have used rosin throughout the period but always searched for alternatives. Recently I bought RMA-223 from china which I'm reluctant to use on anything important (I fear the Cinol story will happen again) and this no-clean flux from mouser http://eu.mouser.com/ProductDetail/MG-Chemicals/8341-10ML/?qs=%2fha2pyFadugjDmQk%2fpfUAqZeS3Ct%2fdkCs%2fU5EyLx6u4%3d which I haven't really tested yet.

[RayRay]

Personally, I use this flux (and just apply with a tooth pick):
http://www.banggood.com/NC-559-ASM-TPF-Flux-Anti-Wet-No-Clean-100g-Cream-AMTECH-Solder-Paste-p-975156.html
It's not an original Amtech flux, but works perfectly fine (and the price>quantity ratio is excellent also!)

[nuno]

They are different things that are only synonyms under very restrictive interpretations.

Rosin is the solid component of pine tar, exclusive of liquids such as turpentine. There are many kinds of pine, so (...)

In Portuguese we call "resin" to "rosin".
And yes, "welding" and "soldering" are the "same", actually, say "arc soldering" or "mig/tig soldering", so we shortcut it to "soldering" when in context, no translation for welding.

I've never seen such a mess in a soldering work. rmendes, you can usually buy the appropriate flux in any electronics store physical or on-line here in Portugal (we even used to manufacture it, not sure if still do), PM'me if you need pointers.

[TheDane]

It looks like you need to clean your PCB's after soldering!

The remaining solder joints looks ok, it's hard to determine if it's done on an assembly line - or if you have re-touched the IC by hand later.
No matter anyway, a good clean-up is needed before it gets to this state.
Getting the correct flux/soldering paste might do it, time will probably let you know - the bank might not like it though

Acids and salts can be present on a board, and can be almost invisible to the naked eye.
It can also be quite hard to clean, so use the recommended cleaner.
(And do clean the entire board, not just particular spots - the nasty stuff can and will move around, it's just a matter of time)

On a different note - it can also be moisture damage resulting from dried up saltwater. (It conducts and etches)
Do you have a kind of hot-spot, thermal vent hole or convection area moving large parts of air over that particular spot?
- not speaking of direct moisture settling/spraying as that should be a no-brainer 

[janoc]

Well, re that Castoline flux:

This is in the description:

"3030 FP/3030 ECO. 3030 FP/3030 ECO. 220º. 240º. 250º. 260º. SOLDADURA FUERTE sobre Cobre / Latón/ Inoxidable. Refrigeración. Industrial. Climatización."

I don't need to know Spanish to know that this is not something you want to put on a circuit board. That's a plumbing/brazing flux.

[james_s]

"3030 FP / 3030 ECO 3030 FP / 3030 ECO 220º 240º 250º 260º STRONG WELDING ON BRASS / BRASS / INNOVATIVE Cooling Industrial."

Sounds like maybe it's intended for brazing refrigeration lines and fittings.

[Cubdriver]

Yep - that's soldering/brazing flux.  Bad (as you've discovered) for electronics.

-Pat