[sdiy] SMT in a toaster oven

[Eric Brombaugh]

On 02/26/2010 03:17 PM, mark verbos wrote:
> I just tried using a small convection toaster oven to reflow some SMT
> parts.
>
> Woah! It work perfectly.
>
> This circuit board is about 6" x 8" and FILLED with discrete parts.
> Soldering it by hand takes me about 20 hours of labor and looks like
> shit.

How many parts are on that board? I find that hand soldering
SMT with tweezers & a fine tip is slightly faster than through-hole 
(less board flipping, no clipping), but I typically don't have more than 
50-60 parts on a board. If it's taking you 20 hours to solder then you 
must have some serious number of parts.

> I stenciled solder paste on it and placed all the parts by hand in
> about an hour and a half, reflowed it in 90 seconds. It looks like a
> machine did it.

The neat thing about reflow is that surface tension on the solder pulls 
the parts into almost exact alignment, and the fillets/meniscuses 
(meniscii?) are gorgeous.

> Do all of you SMT guys do this?

I've used a hot plate to reflow parts with leads that I can't reach with 
an iron (SD card slot with pins underneath, chip-scale packages,  etc). 
This works nicely, but generally all other SMT stuff is done by hand. 
The stencil cost is mainly what keeps me away from this, particularly 
since I'm only doing onesy-twosy quantities for personal use.

Eric