I agree with other respondents, feeling that three minutes at 235 will dull the fillet
and discolor the board.
The IPC-A-610B does not require solder flow on both sides of a PWB at sites with
machine inserted pins. I would not expect a solder fillet to form on lands of the
secondary side of the board in your application. 75% vertical fill is acceptable.

DEEPAK KURIYAN wrote:

> Hello Technetters,
>
> We are doing a job of soldering around 4500 pins into a Glass Epoxy
> Multilayer PCB of size 288 x 200 mm. The pins are first push fit into the
> PCB . The pins protrude on both sides of the PCB . On once side the pins
> will mate with a connector, and on the other side wires are wrapped on. 1
> Solder ring ( 0.9 mm dia ) is then put over each pin . The board is then put
> in a reflow over for 180 sec at 235 deg C. We find that the solder joint are
> not properly formed, and the finish is quite dull. The solder ring is
> composed of 62% Tin, 2 % Silver, 34 % Lead. The solder flows out to the
> other side of the PCB , but is not quite enough. We also notice
> discoloration of the PCB after this cycle.
>
> What are the issues  that we need to be looking at here, to get a better
> joint with a better finish . We are completely new to this .
>
> Appreciate some inputs and tips on doing this
>
> With warm regards
>
> Deepak Kuriyan
> Framatome Connectors OEN
>
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