April 3, 2012
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Soldering 101
A Guide
to the Science and Art of Melting Solder
Chances are that most have used a soldering iron as part of their first accomplishments on the homebrewing workbench ... to assemble a kit, prepare a cable or to build a radio. But how many of us ever had instruction from an Elmer when we first starting using that $5 radio Shack pencil iron or that 35W Weller Soldering Gun?
Here's a chance to participate in a discussion that overviews the many aspects that we each have mastered(?) over the years. We can compare notes, toss in our own experiences of successes and failures, and offer general guidance to the newcomers in the homebrewing ranks.
73,
~George N2APB & Joe N2CX
Audio Recording ... (Listen to MP3 recording)
Text Log ...
<20:16:10>"N8ET - Bill": www.kangaus.com
<20:35:58>"George - N2APB": madelltech.com
<20:36:32>"George - N2APB": weller solder stations ...
http://www.all-spec.com/products/Soldering_and_Rework%7CSoldering.Rework_Equipment%7CSOL-10/?brand=Weller&gclid=COSX8-H5ma8CFQfe4AodqXP8cg
<20:38:10>"George - N2APB":
http://www.madelltech.com/m3.html
<20:41:15>"George - N2APB": Brass wool from Digi-Key ...
http://parts.digikey.com/1/parts/1850504-replacement-wool-wdc-2pc-0051384099.html
<20:42:23>"George - N2APB": acid core solder = no no. Nearly impossible to get
the acid flux outta there and eventually the joint (and electrical connection)
will corrode.
<20:43:30>"George - N2APB": Rosin core is the best for us to use. Rosin melts
and keeps air away from the joint during soldering. Usually no need to add
extra flux. better one from Europe is "multicore".
<20:44:07>"George - N2APB": Water soluble solder is usually not good for amateur
use. Hard to get it all off without leaving some gray trace of it behind, which
also tends to corrode in time.
<20:44:32>"George - N2APB": 60/40 (or 63/37 with lower melting point) is better
for us to use.
<20:44:59>"George - N2APB": Common sizes is 015" (size of hair) for SMT use,
especially.
<20:45:13>"George - N2APB": 031" is better suited for larger-leaded parts.
<20:45:30>"George - N2APB": 128" solder not great for electrical components.
<20:46:49>"George - N2APB": ROHS (no lead) is come to be the better
environmental solution (no Pb), but it has problems in time ... "Tin wiskers"
actually grow and ultimately short out connections. Hi-Reliability industry
does NOT use ROHS solder for this reason.
<20:55:29>"Joe N2CX": 1206 is .12" x .06"
<20:56:04>"Joe N2CX": 0805 is .08" x .5" Decimal, not metric!
<20:56:43>"Joe N2CX": Make that .08" x .05"
<21:00:09>"Joe N2CX": Convection oven
<21:09:18>"George - N2APB": To see several thousand soldering demo videos on
YouTube, do a search there using "soldering tutorial"
<21:09:28>"George - N2APB":
http://www.youtube.com/results?search_query=soldering+tutorial&oq=solder&aq=1&aqi=g7g-s1g2&aql=&gs_l=youtube.1.1.0l7j0i10j0l2.774l1217l0l3885l6l4l0l0l0l0l183l536l1j3l4l0
.
<21:13:06>"George - N2APB": Wahl portable/battery solder iron ...http://www.starkelectronic.com/wahl.htm
<21:14:05>"George - N2APB": Flux pens are very handy to use for making great
connections ... Digi-Key
http://ca.digikey.com/1/3/rosin-flux-pen
<21:15:05>"N8ET - Bill": Bruce of EAE Sales
www.eaesales.com will be at the Timonium hamfest - he has everything for
soldering!
<21:16:07>"N8ET - Bill": Thanks George!
<21:16:45>"N8ET - Bill": W1REX
<21:17:38>"Terry WB4JFI": QRP ME Island cutter kit: http://www.qrpme.com/?p=product&id=IC
SESSION NOTES ...
1) Solder Stations
$5 Radio Shack ... No!!!
$35 Weller .. Good
$75 Weller temperature Controlled ... Better
$100 X-Tronic 4000 ... Best!
2) Solder Tips
· Normal (.062”)
· Fine (.032”)
· Super-fine (.015”)
· 750 to 800 deg. F
3) Solder Types
· Rosin core
· Acid Core
· Water Soluble
· 60/40 or 63/37
· .015”
· .031”
· .128” for auto radiators and lawn art
· ROHS – just say no
4) Other tools
· Fine tipped needle-nose pliers
· Flush cut clipper
· Fine tipped tweezers (non-magnetic)
· Toothpick to hold SMT components in place
· Solder wick braid
· De-solder bulb or solder-sucker
· Anti-static mat
4) Health Considerations
Fan to blow solder smoke away from your face
Vent to such harmful fumes out of the shack
· No food on workbench
· Wash hands after handling solder
5) Viewing Aids
Good light
Magnifier, magnifying visor
Web cam or VCR camera with zoom capability
6) Soldering Components to a PCB
Leaded: axial, radial,
Connectors: pinheaders, BNCs, edge connectors
SMT:
Rs and Cs: 1206, 0805, 0604
DIP ICs
SOIC
QFP
7) Typical Solder Techniques (leaded components)
Hold until joint is hot
Touch solder to the component lead
Use enough solder to make a little “tee-pee”
Don’t move until joint cools (to dull silver)
Clip off excess lead
8) Multiple SMT Solder Techniques
Carefully align, tack corners to hold, then solder each lead individually
Carefully align, tack corners to hold, flow solder indiscriminately, and wick off excess. (The retouch each lead to reflow.)
Doofus hold-down method
Oven reflow method
9) Inspection
Check for shorts, opens, lifted leads, tombstoned Rs and Cs
· Magnifier and bright light help
· Or take macro photo and enlarge on screen
Continuity check
Check for thru-hole continuity
Check for fully etched boards (to catch trace-to-trace shorts in pcb artwork)
10) A Clean Workbench ...
The following is original work of N2APB as contributed to the ARRL Handbook, chapter 23 ...
The "Doofus" SMT Hold-Down Device ...
KD5SSJ "SMT Soldering Tools & Process" (http://kd5ssj.com/solderpaste/smt-tools-and-process)
REFERENCES
1. 1) N5IB SMT techniques including “Doofus” hold-down device: http://www.qsl.net/n5ib/surface_mount/Smk30.jpg
2. 2) Cash Olson KD5SSJ soldering tools paste and process: http://kd5ssj.com/solderpaste/smt-tools-and-process
3. 3) Lady Ada SMT Tutorials: http://www.ladyada.net/library/smt/index.html
4. 4) X-Tronic 4000 hot air solder station: http://www.ebay.com/itm/X-TRONIC-4000-HOT-AIR-REWORK-SOLDERING-IRON-STATION-/120571221985
5. 5) KD1JV SMT Soldering YouTube video: http://www.youtube.com/watch?v=Ah5HEjDTHUo