Soldering BC109C's

Started by lldrew, June 26, 2006, 07:50:33 PM

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lldrew

Im about to solder a few BC109C's and dont have any sockets and dont even have enough money to order any either :icon_eek: So is it ok if I just use a heat sink on each leg and wait a few minutes between soldering legs or do I REALLY need sockets. 

cd

They're silicon transistors, no heatsinking necessary if you can get in/out quickly.  Practice on a piece of scrap if you're not sure.

Unbeliever

What I do with transistors, FETs, ICs etc is to solder one leg of each device (maybe two with ICs on opposite side of the chip) first on *all* of them, the next on all of them, and so on until all legs on all devices are soldered in. This 'spreads out' the heat application whilst still keeping things moving from a soldering point of view (although this is only really important if you are doing more than one of a particular PCB or are a non-casual builder). I don't use any heatshrinking, and probably have my soldering iron temperature hotter than average ... the 'get in and out quick' hits the nail on the head.

lldrew

Well, I heatsinked each tranny and soldered one leg at a time and waited a few minutes between each leg, I was in and out pretty quick.  Im praying I did not fry my trannys.  Think Ill be alright?

Paul Perry (Frostwave)

I'm sure you'll be right, especially if you got the pinout right.. something I don't always do  :icon_redface:
Seriously, it's pretty hard to fry a silicon transistor.

reverberation66

yeah, I don't think heat is your biggest concern here, soldering straight onto the board should be cool with those.  I really prefer using sockets with transistors just because I've been known to get the pinout wrong, and sometimes the layout/schem has it wrong, and sometimes the transistors you use don't sound the best and you want to try other ones...if you have a radio shack nearby you can get two 8 pin IC sockets for roughly 60 cents.  In a pinch you can cut those in half and they make suitable transistor sockets.

markm

I'm kinda "old-school" with trannys.
I don't like sockets and only use them for testing.
afterwards, I remove them and solder the tranny to the board.
It's a personal thing for me, I guess it's the look of the socket
that bothers me. Crazy huh????
IC's, I always socket and leave them.

Ge_Whiz

In 33 years of soldering I have never managed to fry either a silicon transistor or diode. If you're starting out, or not sure, the heatsink is a good idea but it doesn't need to stay on more than 10-15 seconds after you remove the iron tip. Your BC109s are safe.

A bigger threat - though probably still not great - is repeatedly repairing a cold solder joint through underheating.

lldrew

why would it be bad to leave the little heatsink clip on the legs for more than 15 seconds?