Comment by actinium226
12 hours ago
Neat! I just sent out an order to JLCPCB for an ESP32 based board. I don't have a rework station or any experience with SMT so I decided to go for their assembly options. It's 80 per board, but would probably be cheaper per board if I got more than 2 (I also have more components on my board than you).
Question about the instructions in your README, you say that once you're done with the top side, repeat for the bottom, but when you're working on the bottom side, what stops the elements on the top side from falling off once the heat passes through the board and melts the solder on that side?
Working on the bottom side I only used the heat gun really carefully on the resistors then used a soldering iron with a fine tip for the usb-c connector since the leads are fairly large.
Surface tension of solder in liquid state can hold the parts while upside down. Depends on weight of component & geometry of pads
"Bottom side must be done using a rework hot air gun, not possible with hotplate."
Basically you're hoping the bottom side doesn't get hot enough for everything to move or fall off.