I want to do very low volume hobby smd reflow, been doing with hot air station and want to try oven.
I want to dip my toe in the water with the "watch it through the glass & thermocouple" approach, i.e. no microcontroller running a profile.
Basically, all I'm willing to invest in now is:
1. cheap toaster oven
2. multimeter with thermocouple I'll just wedge in through gap in the door mounted to a bare pcb or something with capton tape.
If you're doing it this way (or used to), would appreciate the amazon links to toaster oven & meter/couple you're using. Trying to avoid guessing and finding e.g. the door has no gap to run in a couple wire, etc. Otherwise I'll just guess. Really looking to keep this under $50 US. Thanks.
I use a cheap (WalMart) GE brand toaster oven with 4 heating elements. These are straight rods about 1/4" diameter that run horizontally, left to right. Two above and two below the rack. It has a thermostat that is outside the chamber, and so must work by self-heating due to the current.
I bought a ramp and soak thermocouple controller, that allows a thermal profile to be entered -- heat to 180 C, hold for 1 minute, heat to 245 C, hold for 1 minute, cool to ambient in 2 minutes. I lucked into a lifetime supply of micro-size thermocouple extension wire. I poke the thermocouple into a
plated-through hole in the PC board, thus the controller is monitoring the true temperature of the board.
I have done over 2000 boards with this setup, and it works great. Don't forget to put the thermocouple in the hole in the board, or the boards will
go up in smoke. Apparently, the PC board material and the ICs are great IR absorbers, and the thermocouple just hanging in the air is NOT!
I made that mistake ONCE, only.
I can do 4, 6 or 8 boards at one time, depending on size.
Jon