[solved] Soldering breadboard copper circles keep coming loose

Why is that? Is my iron too hot, or is my breadboard crappy?

I presume you mean protoboard, not breadboard?

If its single sided, yes, its very likely for the pads to fall off. Principle reasons for overheating
with a soldering iron are having the iron too hot or too cold. If too cold you take more than
a second or two on a joint, which cooks the board. Too hot and the board chars immeditately,
just right and you can solder quickly and efficiently.

I suggest investigating stripboard and tripad board, in my opinion much more useful for
prototyping anyway.

In general plated-through holes are much more resistat to pads falling off, so double-sided
prototyping board is another option if you can find it.

Thanks!

Another cause for having the solder iron on too long on the pad is that the pad may have developed an oxide coating, preventing the solder from adhering quickly. Whenever I use one of those boards I first lightly rub a pencil eraser over the pads followed up with an alcohol wipe. Then I run a flux pen over the pads. This makes soldering a whole lot easier and minimizes pad lift. (The eraser will quickly turn black, rubbing on something like denim gets rid of the black).
As MarkT suggests, the boards with plated thru holes are much better, the ones I have the plating keeps the pads bright and shiny, seem to resist oxidizing and make soldering a whole lot easier. They are very easy to find on Amazon.

Some boards have a protective lacquer to prevent oxidation, wire-wool can remove this and give
a more wettable surface, but if you use wire-wool be very careful not to leave pieces of it to short out
traces.

Scotch-brite (green scouring pad) works well too, and leaves no dangerous bits behind.
The main reason for lifted pads/tracks is using a poker instead of a proper temp controlled soldering station.
Using force is another one.
Leo..

I always use protoboard with through-plated holes. Costs quite a bit more than the single-sided boards (50% or so - so the boards are still being pretty much dirt cheap), solders much more easy, and the parts are much better attached to the protoboard (almost impossible to pull them off the board, the single-sided is not nearly as strong). These boards are usually dark green in colour, while the single sided ones are yellowish.
I've discarded my remaining single sided boards soon after I got the doubles sided ones. They're that much nicer to work with.

wvmarle:
These boards are usually dark green in colour, while the single sided ones are yellowish.

Yellowish brown is resin paper laminate. Used for cheap, short-life consumer rubbish such as toys and remote controls. Not suitable for engineers. :grinning:

Dark green is proper fibreglass.

Fibreglass is more tolerant of temperature, but only upto a point - I've encountered some chinese
stuff that was awful (charing very quickly in normal conditions, smelling of chemicals). Presumably
the resin wasn't properly cured in that batch. Go with FR4 the standard flame-retardent pcb formulation
if possible.

The green is soldermask, it tells you nothing about what the board's made from!

It does tell you the production process uses solder mask (they won't do that just because), so they didn't simply glue copper rings around the holes or however those cheap boards are made.

Most important to me is the double sidedness of those boards. Makes it much easier to add some SMD components (such as SOT23-packaged MOSFETs) on the board.

MarkT:
The green is soldermask, it tells you nothing about what the board's made from!

Nevertheless, the colour of the board, not the solder mask, is indicative. It is usually fairly obvious which is board and which is solder mask. I don't recall seeing paper laminate with a green solder mask, except perhaps a very pale green.