[time-nuts] linear interpolators and itty bitty soldering

SAIDJACK at aol.com SAIDJACK at aol.com
Fri Jun 30 19:11:18 EDT 2006


Hi Brooks,
 
another technique that works well with a bit of practice (hopefully not on  
$28 parts...) is to use a heat gun:
 
You can get a heat gun for soldering online for <$30, or buy one at Home  
depot (paint stripper heat gun - be sure to get one with temp control!).
 
Wet the PCB pads with leaded solder and a good iron. Make sure not to put  
too much solder on to the PCB. You may also want to wet the chips' pads, but  
this is hard to do.
 
Heat the PCB with the gun (gun in one hand, chip with tweazers in the other  
hand) and have the chip in the vicinity of the gun so as to pre-heat the chip. 
I  have to set my gun up to 400C to get this going.
 
Once the PCB is hot (>230C) carefully place the chip onto the pads,  aligning 
the pins. The chip will "float" into place if heated correctly and  placed 
correctly. Voila.
 
Randy's suggestion of glueing the chip down may work as well with the gun,  
although I think this would prevent the chip from self-aligning due to solder  
surface tension.
 
The challenge is not to overheat the chip/PCB, to put the right amoung of  
solder (just a tiny bit) and to align the pins when placing the part with the  
tweazers.
 
bye,
Said


More information about the time-nuts mailing list