I am new to surface mount soldering. On a board with both SMT and through-hole parts (header pins), which parts should I solder on first?
I imagine the technique I use for SMT soldering is important. I have access to an oven and a heat gun – baking the circuit board after soldering on my header pins might cause some trouble, but I was wondering that the standard practice was in general.
I read here that
The surface mount soldering must be done before thru hole soldering
because thru hole soldering creates imperfections on the underside of
the board that will prevent good thermal conduction between hot plate
and board.
but this is specific to SMT soldering using a hot plate.
Best Answer
As tomnexus said, it is always best to solder the largest components last. Most of the time this means that the surface mounted devices should be soldered first. Otherwise maneuverability is significantly decreased, trying to navigate around large components to solder the smaller ones.
The other reason I, personally, solder surface mount components first is because I use a reflow oven--I don't want the solder on thru-hole components to melt while reflowing the solder on the SMDs. I put the whole board in the oven with the solder paste and the SMDs, reflow, let cool, then do the thru-hole components with my iron. I wouldn't recommend doing it any other way.