Create breakout for iM880A-L

Question

I currently need to work with the iM880A-L. As it is annoying and shaky to solder that thing on perfboard and attach cables, I want to create a breakout board with JTAG and SWD plug and pins for all the other pads.

How do you actually connect the pads with your board? I never soldered such a big SMD board, so I wonder. Just bigger pads on the board, as in normal SMD like resistors? Is there another standard and stable way to get pins on the iM880A-L without creating a custom board?

Does anyone know some similar board that I can copy from in Eagle/KiCad (did not decide yet)? How do you call these pads/connections on the iM880A-L? I really did not know what to Google, I tried post stamp, as it looks like one, but that just led me to tiny post stamp sized bords. I am a newbie to custom board design, so please bear with me.

Kind regards

Answer 1

The datasheet shows a recommended layout for a carrier PCB (Section 5.3, page 17). The recessed nature of the edge contacts helps ensure a good solder contact that can be properly inspected.

The datasheet also shows soldering conditions using a SMD reflow profile with no guidance on hand soldering temperature and time. See note below.

You could alternatively get hold of some pins with a diameter of no more than 1.2mm (the pad size shown) and crimp or solder wires into these and then solder the pins to the contacts you wish to expose.

Note that the RF output would need to have 50\$\Omega\$ coax if you used this route to interconnect.

Using a carrier PCB, it is suggested that a coplanar waveguide with ground is implemented for the RF interface; you would need to calculate the dimensions for this based on the carrier PCB specifics.

Actually soldering the board to a carrier by hand should not be difficult; just ensure that the soldering iron touch time is minimised. I would suggest no more than 300C iron temperature and 5 seconds application time (which should be easily sufficient to actually form a good solder joint).