Soldering Coaxial Cable to CMOS Imaging Sensor PCB

[cvickstrom]

For the life of me, I can't solder the coax to the CMOS PCB without a short (if I even get it on in the first place). An tips for this? I have v3.2, with the 2 holes instead of 5 (and much less room to work with). Also, the CMOS PCB I'm working with has a short between signal and ground without any visible solder or anything on it, maybe because I heated it over and over. Is this PCB toast or is there hope to fix it?

[Daniel Aharoni]

Hi cvickstrom,
It is definitely not a good sign that signal and ground appear to be shorted on the CMOS PCB even with the coax cable not soldered on. I suggest closely looking over the surface and components of the PCB using a stereoscope to see if there is any small solder bridge causing the short. While repeated and excessive heating could cause a short within the PCB it is probably not that likely.

You will need to find and fix the source of the short before trying to solder the coax cable to it again.

Also, there are multiple ways to solder the coax cable, some easier than others. What you might want to try is buy a pair of 50mil pitch headers. You could then solder a 2 x 1 female header, https://www.digikey.com/product-detail/en/mill-max-manufacturing-corp/851-43-050-10-001000/ED90265-ND/1212162, to the 2 holes of the CMOS PCB and then solder a 2 x 1 male header, https://www.digikey.com/product-detail/en/mill-max-manufacturing-corp/850-10-050-10-001000/ED8250-ND/279659, to the signal and ground lines of the coax cable. This gives some extra room to work with when soldering and you also have the added benefit of having a cable that can be swapped between CMOS PCBs. The down side is with enough force, the male header can pop off of the female header. The parts I linked to come in a 50 x 1 pin configuration. You just need to break off 2 to get a 2 x 1 header.

[cvickstrom]

Thanks for the tips, it was very helpful! I was also using bad solder.