Soldering the E73-2G4M08S1C nRF52840 module using a Soldering Iron

With the hidden pads underneath the module, soldering it to a PCB using just a soldering iron isn't a trivial task.

Steps:
1 - Add a bead of solder to the inner pads of the E73 module. Make sure that they are not too large and are all the same size
2 - line-up the beads with the holes matching these pads in the PCB. Since the beads will "fall into" the holes they will "fall in place" somewhat. A binder clip will help hold everything together
3 - heat-up the inner pads on the opposite side of the PCB, distributing the heat to all pads so that the solder melt and until there is no gap left between the module and PCB. This will require multiple passes with a larger soldering iron tip to heat more than 1 pad at a time.
4 - Once the inner pads are soldered, change your tip to a conical one with w relatively fine tip (not super fine). You can then start soldering the outer pads. Make sure to keep the head and iron away from the holes of the PCB. Only heat the castellations of the module, apply a little bit of solder and let it flow towards the PCB pad.
5 - Go and solder the 3 sides of the module, one joint at a time.
6 - Once you have all joints done, visually inspect all connections to make sure there are no shorts between pins.
7 - go ahead and test with a USB tester. This will make sure there are no shorts in the power circuitry.
8 - to test the rest, we need to flash a bootloader and some testing firmware on it.

Tools Used:

TS 100 Soldering Iron with 19V power supply (300C setting)
TS-D24 Soldering Tip. This is the Chisel Tip one.
Copper Cleaning Ball for Soldering Iron (ball of copper wool in a metal container)
MG Chemicals 63/37 No Clean Leaded Solder, 0.032" Diameter
TS-B2 Conical Soldering Tip (not very fine like the TS-I)
Small Binder Clip
Solder Wick
Old phone charger

[pjvds]

This was exactly the video that I needed to get the confidence that this module is solderable by hand. Ordering some modules! Thanks

[jeanpaulberrios]

Hi thank you for share the tips to solder, I wast testing e73 with nrf52832 could you share the footprint pcb for nrf52840, best Regards JP