Here's, literally 5 minutes work, with a scrap PCB, some chipquick solder paste, a slightly sharpened wooden kebab stick (no cocktail sticks in this house, it seems) and about 5 mins under the current Mrs MartinM57's kitchen grill, set to max, about 40mm from the element, starting from cold until the solder melted and then the tray pulled out to for it all to cool naturally
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yes, the via holes aren't in the middle of the via pads (but close enough, the PCBs work fine)
yes, I know the middle one should be a cap of some strange size but I put a 1206 resistor on it
yes, the top and bottom resisitors have pads for 1206 size but I put 0805 on
yes, the amount of solder is inconsistent - I was trying different amounts to see what was best - bottom right fairly obviously
I probably undercooked it - it didn't get hot enough to pull the components into line (or there wasn't enough paste to get enough surface tension to pull them)
...but it's not too bad for a first attempt in literally 5 minutes.
There was no fancy temperature profile - it just got hotter and hotter until the paste melted.
It does show that the key variable is amount of paste - it's a small amount but not too small - and it needs to be consistent. A stencil or some sort of adjustable constant (tiny) volume syringe pump is probably mandatory to get reliable results
The PCB pads are HASL (google it ) so the solder on them will contribute to the overall amount of solder on the pads - it's just about enough to tack solder a component on for alignment without using any extra solder at all. If you had plated pads, you would probably need a fraction more paste.
Just need some feedback from Dippy on the Currys oven - PCB reflow good-enough for £25 or relegated (promoted?) to sausages?
Just about what I said in post #8.
Keep it simple .. is is not complicated at all.
Actually the amount of paste is not a big deal unless you go crazy. I got a couple of syringes from the pharmacy, cut the needle off to a short length and use it to place the paste ... Cost 25 cents US.