[sdiy] CMOS IC heat damage

[Scott Gravenhorst]

CD4xxx IC parts are pretty robust and can handle a couple of seconds of
heat from a 35 watt (or thereabouts) iron easily, possibly a little
longer.  I'm not sure what the limit is.  I would definately check for a
bridge or other solder issue.  Or even a deformed socket (from the
heat).  I use a telescope eyepiece as a high power magnifier, a loupe is
another good choice.

Charles Brodeur <orange_juice_man_returns at yahoo.com> wrote:
>Hello All,
> I was working on this design of VCO, found at:
>
>http://www.uni-bonn.de/~uzs159/vco4069.html
>
>I had it working correctly, i.e CV pitch worked, and it produced pulse
>and saw waveforms. I wanted to clean up some of the cheap input and
>outptu hookup I did, so I took the iron to some of the solder joints.
>
>One of these joints was near the IC, which stupidly enough was in the
>socket at the time. One I reconnected the circuit to my power supply,
>It failed to produce any output. Specially I was soldering near the pin
>that produces the pulse out. 
>
>In your expert opinions, could I have damged the CMOS inverter chip by
>soldering near a pin while the chip was socketed? Or should I check for
>solder bridges, which I already have done to no avail?
>
>It was really excited this circuit was finally working. It was a real
>letdown to have something this simple ruin it. Thanks for any insight
>anyone can contribute to this problem. 
>
>-Charles
>
>
>		
>__________________________________
>Do you Yahoo!?
>Yahoo! Mail - You care about security. So do we.
>http://promotions.yahoo.com/new_mail
>

---------------------------------------------------------
- Where merit is not rewarded, excellence fades.
- Hydrogen is pointless without solar.
- What good are laws that only lawyers understand?
- The media's credibility should always be questioned.
- The only good terrorist is a dead terrorist.
- Governments do nothing well, save collect taxes.

-- Scott Gravenhorst | LegoManiac / Lego Trains / RIS 1.5
-- Linux Rex         | RedWebMail by RedStarWare
-- FatMan: home1.gte.net/res0658s/FatMan/
-- NonFatMan: home1.gte.net/res0658s/electronics/
-- Autodidactic Master of Arcane and Hidden Knowledge.