> On Apr 2, 2017, at 12:51 AM, Jon Elson via cctalk <cctalk@classiccmp.org>
> wrote:
>
> On 04/01/2017 11:27 PM, Chuck Guzis via cctalk wrote:
>> What do you do about boards with SMT components on *both* sides? I can't see
>> how it would work with a toaster oven.
> OK, this is going to be long.
>
> I do small-scale production of mostly motion control boards, but also some
> nuclear instrumentation. Mostly 0603 to 0805 passives and SOIC up to 0.5mm
> pitch QFP chips. I use a lot of FPGAs in 144 pin packages.
> ...
>
> One of the tricks I found out very fast was the thermocouple doesn't absorb
> IR the way a board does, the first board I did came out warped like a potato
> chip and nearly black. It occurred the me to poke the thermocouple junction
> into a through-hole in the board, and then it all worked. I still have some
> slight problems with some areas of the oven running a bit cooler or hotter,
> so I have to tweak the peak temp setting sometimes to get all the boards
> soldered.
I have a nice article about toaster oven SMD work. It's in German, via the PCB
Pool website if I remember right. It mentions that problem. The solution
picked in that article was to use a spare board (same or similar layout) as the
thermocouple holder. But attaching to the actual board sounds good.
paul
