Homebrew PCBs

Agreed.  I use a $20 toaster oven.  It is *never* used to heat food.

--- In Homebrew_PCBs@yahoogroups.com, "smilingcat90254" <smilingcat@...> wrote:
>
> I use $20.00 toaster oven. Solder paste for some of my surface mount. TQFPs and other fine pitch devices. 
> 
> Dab a bit of solder paste on a "reference" pad and watch for the solder paste to melt. Easier to keep track and when you see it melt immediately turn off the oven, wait about 20 seconds and pop open the door. poor mans way of trying to mimic the reflow temperature profile.
> 
> Have a dedicated toaster oven and do not use it to heat food!!. 
> 
> One of my project is to build a simple controller to do this. so I can actually meet the reflow temperature profile. It's easy but have too many other things right now.

I use a USB thermocouple to plot the temperature in real-time.
The one I use is the TEMPer1K3 from PCSensor.Com for ~$25.
The TEMPer1K4 is ~$20.  The former has electrical isolation
whereas the later does not.  This probe has a button that causes
it to behave like a keyboard and start "typing" the current
probe temperature once a second.

I banged together a Python script that plots the temperature
in real-time:

  http://gramlich.net/projects/temprof/temprof.py

A target temperature profile is:

  http://gramlich.net/projects/temprof/leaded_profile.csv

I actually control the temperature by opening and closing
the toaster oven door by small increments.  Eventually, I
want to control the toaster over with a solid state relay,
but until then the manual control works well enough for me.

For a total cost of $20 (toaster oven) + $25 (usb thermocouple)
= $45 I have a solution that works every time.  I do get an
occasional solder bridge, but that is more of a function of
me still learning to apply solder paste via a solder stencil.

Regards,

-Wayne