How to avoid overheating germanium while soldering?

[mike_a]

I have a soldering question:

Up until now I have been using sockets for transistors.
I've heard that this could be a problem because they can fall out of the sockets with the right amount of shaking.
So I wanted to ask what the proper way to solder transistors is.
I've heard about using tweezers/pliers to cool the leads, but I didn't understand where I was supposed to put the pliers (I know - silly question).
I would imagine putting them on the component side of the PCB and not on the solder side because that would interfere with the soldering, but maybe I'm wrong...

also, what should be the correct heat for soldering trannies? (to cold and you have to hold it long; too hot and you fry the tranny)

Thanks,
Mike.

[JiM]

I've heard about using tweezers/pliers to cool the leads, but I didn't understand where I was supposed to put the pliers (I know - silly question).
I would imagine putting them on the component side of the PCB and not on the solder side because that would interfere with the soldering, but maybe I'm wrong...

You're perfectly right. The pliers act like a sort of heatsink, giving more thermal inertia to the lead, thus more time before the heat spreads into the semiconductor.

also, what should be the correct heat for soldering trannies? (to cold and you have to hold it long; too hot and you fry the tranny)

Your concern is remarquable, but i think it's necessary only for germanium transistors (unless you have a plumber-type soldering iron, which would be too hot and too big for electronics anyway). I use a 30W unregulated iron, with fine tip, and i just try and be quick when soldering silicon transistors. And maybe not solder all three leads in a row but wait a little after each. While the case is cool enough to touch, it's fine (too hot to touch ~60°C, Si damage begins between 90~120°C).

For Ge i use sockets.

[mike_a]

Thanks a lot Jim!

I will try this technique on my upcoming build.