chips vs chad
hilpert at cs.ubc.ca
Fri Apr 9 15:32:33 CDT 2010
Fred Cisin wrote:
> > > We used a special Weller tip. It consisted of metal block (about the
> > > same size and shape as an IC base with holes where the pins would be)
> > > attached to a Weller tip sleeve (ie the part that held the tip to the
> > > heating barrel) On the component side you had a spring loaded clip
> > > that exerted even pressure on the chip away from the board. Apply said
> > > tip to the copper side of the board and the chip came out complete.
> > > Then the solder sucker was used to clear out the holes.
> On Thu, 8 Apr 2010, Chuck Guzis wrote:
> > I remember those--you could get them in various patterns, such as a
> > round cup for TO-100 packages. (I may still have one somewhere for
> > my Ungar iron). My recollection is that as manufacturers went to
> > multi-layer PCBs and buried ground planes that the amount of heat
> > required by the iron to perform the job got to be ridiculous. The
> > only DIP version I've seen worked with 0.300" wide 14/16-pin
> > packages. I've never seen one for a 40- or 64-pin DIP.
> I've never seen one the right size for chips and chads.
> I saw one for 40 pin ICs. It did not work as well as desoldering one pin
> at a time. My friend who had it stuck it in a drawer.
I received a 14/16-pin one sometime ago. Not very useful IME. Getting thermal
contact on all the pins to get them molten simultaneously just doesn't work out
well, especially on wave-soldered boards that are light on solder or boards
with small pad areas (i.e. anything after about 1978). 10 pins are overheating
while you're still trying to get another one to melt.
I tend to stick with my 1970's Soldapullt (solder sucker), some wick on
occasion, and working through the pins one-at-a time.
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