Mail*Link(r) SMTP               FWD>ASSY: Solder in Connector Pins

Greg,

We experienced similar problems with the ol'DIP formed sheet metal sockets
from some manufacturers.  Sometimes the DIP IC's were inserted into the
sockets (to add more mass and keep the sockets from "floating" during flow
soldering).  Frequently, the DIP's were soldered into the socked as well as
the socket into the PB.  This was not a happy occasion when you needed to
change a DIP IC. (;-)

The problem was that the surfaces of the socket contacts was very solderable,
coupled with a good flux and soldering operation the solder would
wick/capillary right up the hollow core of the socket.  Depending on how the
socket contacts were formed determined if the solder would wick/capiilary up
to the component lead and solder it to the socket contact.

We went after the socket manufacturers, a couple made slight changes in how
they formed the contact to "pinch off" the hollow contact, some others added a
polyimide film to work as a plastic dam to seal off the hollow contact between
the socket body and the PB.  Others didn't do anything and we dropped them
from the "approved" component suppliers.

Your description reads like you are having a similar problem, IMO you've got
to some how seal off the hollow core of you contacts to eliminate the wicking.

Ralph Hersey
[log in to unmask]

--------------------------------------
Date: 8/1/96 11:51 AM
From: [log in to unmask]
          I am experiencing a small amounts of solder in the pins of a 44-pin 
          D-SUB connector after wave solder. The solder is very difficult to
see 
          without magnification. The pin type is formed and rolled. The 
          connector manufacturer thinks that the combination of an the active 
          flux used and flux application method, spray fluxing, is the root 
          cause. However, when the connectors are replaced, a hand soldering 
          process is used, yet the pins still fill with solder. I would
greatly 
          appreciate any input.
          
          Thank You, 
          
          Greg Kilinski
          Acuson Corp.
          [log in to unmask]

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