I wanted to add a small reflow oven to my workshop for some time now but only recently decided to actively look for specific info on the subject.
There are of course small commercially available ovens like this one, but it appears that it has issues with excessive heating on darker components due to the IR heating method used.
Other better quality commercially available ovens are way to expensive for my budget and I am now seriously considering converting a mini oven for this purpose. There seems to be tons of info online of people already done this and there are also ready made arduino based PID controllers like this one.
I am however having trouble choosing a suitable mini oven from the EU market (it seems there are far more choices available in the US ) .
I wouldn't like to just blind -buy some small oven only to find out later that it is either difficult to modify, underpowered or has some other flaw for this job.
Has anyone tried this mod recently with a particular mini oven preferably available through amazon or some other online retail store? Any other related suggestions also welcome!
I recently bought the QS-5100, which seems to be an improved version of the T962A.
Haven't tried lead-free paste yet, but very happy with the results of lead solder paste (used 220C reflow).
Leo..
I recently bought the QS-5100, which seems to be an improved version of the T962A.
Haven't tried lead-free paste yet, but very happy with the results of lead solder paste (used 220C reflow).
There is talk about this version and reviews here:
I think accurate temps is a problem with all ovens, and a DIY oven could be worse.
When I use the QS-5100, I do a dry run first.
And let it cool down until the cooling fan just turns off (<70C).
That way I'm sure oven and room temps are not a factor, and a repeat flow will be the same.
So far I have used ~80x100mm boards, and used only one at the time in the middle of the tray.
My boards have mounting holes.
I put a screw/nut in those holes, so the board is resting on the screw heads.
Nice and low (away from the elements), but off the bottom of the tray.
I use stainless steel solder stencils if possible, for even amounts of solder paste.
So far I had consistent reflows, without burning.
Leo..
The only temperature control you really need is for the soak period, since that should not
go too high. After that you can just apply full power and watch the solder reflow, ensures
complete reflow without much effort - you can tune how close the board is to the heating
elements for optimum results too. The cheap oven I got had a temperature control of sorts
and a timer, which seems to work fine - all I did was move the bottom heating element to the
top and space the two elements out a bit for an even heating area. Forget the model,
very cheap ALDI special!
In other words you don't need accurate calibration to get it to work. Of course if you want
truly repeatable results you need to have temperature profile control and to calibrate the oven,
but for prototyping on a budget its a luxury really.