HELP! - Soldering Novice Question?

mpireone

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Feb 12, 2009
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My solder isn't sticking to the circuit board, what am I doing wrong?
 

Gunner12

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My limited experience says flux and make sure the board is hot enough. Also make sure the surface is clean.

This thread might be better in the Custom and Modified section.
 

Morelite

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Some PCBs have a protective coating on them to prevent oxidation and corrosion.
 

kuksul08

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make sure you are using good solder... 60% tin and 40% lead or near there. Also the board pads need to be just as hot as the leads for the solder to flow onto them
 

LukeA

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You said you were a novice, so: have you fluxed the board? You need to apply flux for the magic to happen.
 

rx78gp02

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You said you were a novice, so: have you fluxed the board? You need to apply flux for the magic to happen.


Nimber one reason why solder doesn't stick to component. A little flux to the terminal and a little solder on your iron, then bring the two together. Once the flux has been evaporated/burned gone, then add more solder to secure the component.
 

VidPro

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just soes you guys dont confuse the newbie, most of the consumer solders have flux IN the core of the solder (read the package on what you have).
if the surface is clean, free of oils and paints and covers, and stuff, the flux in the flux core solder is usually enough to flux the contact point.

light sanding or scraping of the contact point, gives you the raw unoxidised metal to solder too. depending on the thickness of the contact, you can get away with a harsh sanding or a light 400grit type of abrasive cleaning, even stuborn covers can be removed with zacto knife scraping, as long as you dont destroy the whole surface..

some metals are neer impossible to "solder" to , but that shouldnt be a problem on most curcuit boards, but can be a problem on other connections you could try and make.

flux IN the solder seems to have a temperature point where it is most effective, to cold and it doesnt clean, to hot and it charrs and doesnt work. so you want the flux that is IN the solder to hit the contact point when its already heated, so Solder gun heats contact, then in-solder flux hits point, flow occurs, and then you stop quickly. You can also get solder and flux on the tip of the gun and transfer it, but at first that is trickier to do effectivly, especially if your having the specific trouble stated in the thread.

some curcuit boards are very good heat sincs (like led stars), without heat, the flux wont flow and "clean" and solder wont flow and stick.
more watts on the solder gun, or more temp on a solder station makes more heat , when the componets keep drawing the heat away too quickly.
another reason i like excessive solder gun heat, is you can/Must move much faster, which keeps heat out of areas that dont want it. then it happens faster, and your in and out faster.
anyways
if you heat Sync a thing your trying to solder in some way, which may even include it sitting on a cool thing, or being held/clamped with a cool thing, it can drive you up the wall when it wont heat up, especially with a lower wattage solder item.

Is better to TIN (as they call it) or achieve solder flux flow on BOTH items , like the contact and the wire, once both items have solder on them, then allow it to re-cool a bit, then heat both together for assembling. that way your not overheating everything trying to get the 3 things occuring at once.

excess flux is also supposed to be removed when your done, because it can continue to "clean" things under various conditions, so if you use a paste or liquid flux, you should remove it when done to reduce corrosion.

note: i never said i could solder :), without blobs, and teats, and overrun, and cold joints and things, but those are a few things i learned when messing with the stuff.
 
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Superdave

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Buy solder with flux core !


x2

I'm a bench tech (among other things) for a living, when i'm working on my lights i usually set my Weller to 800F, with a completely clean tip i'll dab a bit of flux core'd solder on each side, then pack a small dab on the iron's tip and join the pieces that way. When both surfaces have the same solder things are predictable. I tend to solder at higher temps like vid pro says, hotter and faster seems to do less damage to things then slower and colder.

When i work on monitors and other things, most of the stuff has a higher melting temp and is lower grade solder which makes component replacement a chore sometimes.

always remove excess flux when you are done, flashlights are fairly low voltage but flux is capacative/conductive to an extent. It's always good practice to clean up everything with flux remover or a small wire brush.
 
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