8 Apr
2010
8 Apr
'10
10:35 p.m.
On 9 Apr 2010 at 6:17, Rod Smallwood 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.
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.
--Chuck