In a message dated 8/12/00 12:47:29 PM EST, [log in to unmask] writes:

<< Hi Technos,

 I have, once again, the opportunity to bother you with a delicate matter.

 I had to reflow some boards having PC104 connectors on them. Unfortunately
 somebody else made the decision to chose the ones with solder rings around
 the pins, supposed to reflow and give nice joints. The samples I had
 soldered very well on the sample board supplied by the vendor of the
 connectors.
 Now the surprise: in the real situation, the prototype boards I had to
 build, show no joint at the PC104s. The solder rings didn't even bother to
 melt. And the profile is good, the temp on the pins reached 205C.

 So I have two big questions:
 1. how to rework the connectors?
 2. what to do in case we should give it another try? Sould I even try it
 without going into intrusive reflow?

 Thanks,
 Ioan >>

Hi Ioan!

At the last place I worked at we did PC104 cards. We first started out doing
the connectors by hand...at about 20-minutes per (that's both the short and
long one). Then we checked out Teka connectors (they have solder preforms in
them). It was a last step that we did, because the boards did have other PTH
components in them and the boards were waved...as you know can't wave a PC104
connector. What we used was a hot air deal that was made from Leica. It works
great! does the whole connector in about 2.5-minutes. If you have all SMT and
are trying to do everything in reflow, it's important that you pre-flux the
location. If that's doesn't work, then maybe it is important that there is
heat concentrated at the pins and barrels as with the Leica unit that I
used...the Teka guys can turn you on to the unit.

-Steve Gregory-

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