Well, back from a short break away (kid free woohoo!) and onto some widget builds. I thought I’d document how I do my widget construction. I actually find building SMD devices much easier than the PTH variety.
I have all my components in some neat snap together containers, this allows me to have everything at hand for the build.
[Click on images for larger size)
1) Solder paste is applied to the boards sparingly, ready for component placement
2) Components placed on each board, I usually do a board at a time. You will see x3 boards without any RF modules, these will be added at a later time depending on what band is required.
My SMD toaster oven setup.
The toaster oven is unmodified straight out of the box connected to the PID temperature controller.
PID Ramp controller with Solid State Relay output driver from E-Bay, that allows me to store up to 64 different temperature/time steps, each step can have their own PID parameters. The ramp controller allows me to set and store my solder temperature profiles and when enabled will cycle through the temperature profile.
The PID controller is installed in an external SCSI case I salvaged from an old external tape drive.
The thermocouple is a K-type with the shroud removed to give a fast response to temperature changes, I also have it wired to a spare PCB to give me a good indication of the PCB surface temperature in the oven
Rear of PID controller case, I’ve wired a power point directly a 10A solid state relay and fuse. The SSR is driven by the PID output, so power is only applied when heat is required. This allows me to use any unmodified toaster oven.
Batch ready for baking, carefully placed onto tray so no components are moved in the process.
All I do now is start the Temperature controller and let it do the rest (after closing the door) Since the Toaster oven is unmodified in any way I just turn it’s temperature knob to the max temperature and the same goes for it’s timer. The bottom power light turns on when temperature controller is heating.
My hi-tech fuse and bootloader programmer ready for programming. The headers give me good connections and allows for easy changeover.
Fuse and bootloader being programmed