[hpsdr] Atlas, How do I hand solder this thing?

[Robert McGwier]

For quite some time I have taken the bull in the china shop approach 
with 100% success (and it has the benefit of appealing to my nature ;-) 
).  Tack the corner and then get solder everywhere on the remaining pins 
for the IC (either DIP and quad leaded).  The detailing is then done 
with solder wick to remove the excess and shorts.  Inspect with 
magnification.  This beats the heck out of attempting to solder single 
leads at a time.

Bob




Steven Bible wrote:
> ***** High Performance Software Defined Radio Discussion List *****
>
> The two iron or twezzers method is for all the two lead parts (caps,
> resistors, diodes, etc.).  The idea is that the part will position itself
> using surface tension when the solder is in its liquid state.  Very handy.
>
> For multi-leaded parts, the technique depends on the part.
>
> For dual inline parts (SOIC, SSOP, TSSOP, etc.) keep all the pads clean and
> free of solder.  Pick one corner pad and apply a tiny bit of solder.  Then
> with tweezers, position the package over the pads, align, then solder.  Melt
> the solder and repostion as necessary until the part is aligned.  Then
> solder the opposite corner lead.  Now the part should be in position,
> aligned, and you can solder the remaining pins.
>
> For very fine pitch quad leaded parts (CPLD or FPGA), keep all pads clean
> and free of solder.  Of course, a microscope is the best tool for this type
> of work.  Since the leads and pads are very fine, the tinning of the
> soldering iron tip is enough to tack a lead in place.  Use tweezers, vacumn
> holder, tooth-pick-and-bees-wax to hold the package in place.  Tack one
> corner lead.  Then tack an opposite corner lead.  Look and double look to
> make sure you have the package aligned.  Then proceed to solder the
> remaining pins one at a time.  The tendancy here is to use too much solder.
> Try and limit the amount of solder fed onto the pin-pad.  Ample flux helps
> the wetting action.  I do not recommend the flood and wick method.  This is
> simply too dangerous in that you may damage the part from over heating or
> bending a pin.  The major problem with this method can be a solder bridge
> that you will have a very hard time seeing under the pins.  They are very
> hard to find even with a stereo microscope.
>
> Take a look at the Spring 2006 PSR for a duscussion on the choice of a
> microscope
>
>    ftp://ftp.tapr.org/psr/Spring_99_2006.pdf
>
> 73,
>
> - Steve, N7HPR
>  (n7hpr at tapr.org)
>
>
>   


-- 
AMSAT VP Engineering. Member: ARRL, AMSAT-DL, TAPR, Packrats,
NJQRP/AMQRP, QRP ARCI, QCWA, FRC. ARRL SDR Wrk Grp Chairman
Laziness is the number one inspiration for ingenuity.  Guilty as charged!


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