[sdiy] "obsolete" 2N3906

[ASSI]

On Monday 09 June 2003 10:06, Paul Maddox wrote:
> Though soldering a 208pin TQFP was NOT fun ! (Xilinx SpartanII
> 300Kgate device) other than that I've done upto 144 pin TQFP and
> single resistors/caps without any problems.

There's a little trick that can make it much easier. You do have to 
practice a bit with killed chips or empty packages. Put the package 
down flat and just fix two diagonal corners with a needle tip. Check 
the alignment and that the package really is flat, apply a hint of flux 
on the leads. Then get out a larger iron (around 30W or so) with a 
wedge tip and make a good sized bead of solder on the tip (just enough 
so it doesn't fall off). Now start at one of the loose corners and 
slowly pull the solder bead over the leads. Getting the velocity right 
and holding it steady is the tricky part. Go steady, never stop and 
supply new solder as it is consumed. After you've done one side, let 
the package and the PCB cool down. There's typically a few leads that 
have bridges, you can clean them off by touching up with a needle tip 
later. PLCC can be soldered the same way, although you may need a 
slightly larger iron.


Achim.
-- +<[ Q+ & Matrix-12 & WAVE#46 & microQkb Omega sonic heaven ]>+ --

Q series MIDI Implementation & additional documentation:
http://homepages.compuserve.de/Stromeko#WaldorfQDocs