Homebrew PCBs

When i had "jumping chips" it was so bad they would pop right off the
board all the way across the table. This was when i tried to dilute
old no-good solder paste.
So having seen that, i don't think anything can be done once it happens.

You have to get out the moisture. if the parts are the cause, bake
them. If the paste is the cause, dispose of it and get new paste. I
expect it is the paste unless the components are stored in a wet
location.

It is very frustrating indeed, you have just painstakingly stuffed a
board, and then the buggers just hop off one after the other undoing
all your work and there is pretty much nothing you can do except
watch... That'll really ruin your day especially if you have to order
new solder paste (which in effect means even more painstaking hand
soldering with the iron for now).

ST


On Fri, Apr 10, 2009 at 6:08 PM, roycepipkins <royce.pipkins@...> wrote:
> You might want to give Cash Olsen's embossing gun technique a try. His site has gone down now, but the basic idea is to use the hot plate to preheat the components to only 212 (100C) and then blast the leads with an embossing hot air gun for just a few seconds. Long enough for the solder paste to reflow.
>
> I've had an 0805 cap or two pop up on one end while doing this technique and have actually been able to push them back down via the air pressure of the gun. An IC would be forced towards the PCB even more owing to its greater package surface area to lead surface area ratio.
>
> Just a thought.
>
> Regards,
> Royce