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Comment by mastax | Hacker News Reader

Related note: I spent a while trying hand soldering, hot plates, and hot air rework to solder SMT boards. I should've just gotten a cheap toaster oven like in the article. I guess I was scared off by all the people insulating them and installing PID controllers. Totally unnecessary for me. I just stick in a thermocouple and vaguely follow a reflow profile. I'm easily getting 100% successful boards down to 0402 and 0.4mm QFN.

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Same experience here: this board[0] was hand-placed and soldered in a toaster oven by essentially opening the oven door when peak reflow temperature of the paste I was using was reached. Additional aside- I very much prefer Loctite GC paste: it has a non-refrigirated shelf life of 6 or 12 months (however, it seems fine to me even a year past expiration date)

0: https://linx.wot.lv/bvcoyurf.jpg

+1 for Loctite GC paste, used it professionally for prototyping and it has always worked well with crude toaster reflow. Still stuck on hot air and Mechanic paste at home.

Wouldn't it have been easier to just get them assembled? It costs less than $10 with JLCPCB and you avoid tons of hassle. I'm thinking of getting the assembled boards for this cube, if I can, as it looks amazing.

Projects like these are not about the destination, man. They’re about the journey. My guess is that more than anything this was an exercise in learning the processes of soldering small, tightly packed smd components.

Eh sure, the journey is fun the first time, but I personally just get them assembled now because I'm tired of soldering a million small components for the Nth time.

Not wanting to do this, and the OP talking about eyeballing a reflow oven are kinda not the same thing. Not doing an ad-hom attack here, but you probably own a reflow oven.

Eye balling the reflow profile with a thermocouple you threw in there is brilliant! I have a thermocouple readout on my DMM. I could go do this today with parts I have right now. That is wonderful, thankyou!

> Not doing an ad-hom attack here, but you probably own a reflow oven.

I do not, I've never even done reflow. I briefly considered making the toaster, because it's a very fun project, but in the end I think I'm just going to get my PCBs assembled.

neat.

I am huge fan of automated assembly as well, I think it unlocks designs that no one would even start to think about, like laying out thousands of discrete components on a single board. Esp if applying an aspect to a circuit, like "apply esd protection" or "apply bypass caps" or "apply pull low / high".

There's a ton of journey left in the software side for those more interested in that.

The JLCPCB assembly service has a really limited parts selection and in general all microcontrollers and interesting parts are in the extended parts list. So most of the time you are soldering in the critical parts yourself anyway.

I don't need them to solder the critical parts, I need them to solder the numerous parts. I don't mind soldering one MCU, but I do mind soldering twenty 0805 resistors (or 3456 LEDs).

I do get almost everything assembled, from JLC or MacroFab, but I've been tweaking precision analog stuff and I need a fast turnaround and JLC doesn't have the parts.

When I was getting into the hobby I reflowed a number of boards by balancing them on a piece of tin flashing, holding it over a candle or alcohol burner, and trying to seat-of-my-pants my way through the temperature profiles from the back of the datasheet. Yield wasn't great, but I got there, and it was definitely cheap!

When you need to reflow a board while you're living in a box next to the van down by the river... nice!

Doesn't a candle lead to soot deposit?

Yes, but on the tin rather than the board.

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