How to Make NVRAM "Battery Eliminator" Boards

I've been working on a process for creating NVRAM boards that replace common DMD era 6264 battery backed up RAM. Thought it would be helpful for people.

Whilst I've had success with hand soldering the SMD chips the process is fiddly and not for the unconfident solderer, also the results can look a bit messy. So I've started to reflow them using a heat gun and paste. Much easier and cleaner looking.

Here's what I use:

- RAMTRON FM16W08
- SOP28 to DIP28 board (pin width should be 15.24mm)
- Flux pen
- Solder paste
- Sparkfun Heaterizer XL-3000 https://www.sparkfun.com/products/10326
- Isopropyl and toothbrush for cleaning (optional)

I run some flux over the contacts, line up the chip, paint a thin rail of paste over the pins then heat the whole thing. Here's a timelapse of the process:

After that you can use standard pin header (either square or round depending on your socket) and either reflow in the same way or hand solder. Simple!

Have some prebuilt extras if anyone's interested in buying.

Good tip on the naphtha - the isopropyl doesn't quite do the job. As for drag soldering - yes it's better than point-to-point for sure, but reflowing is certainly cleaner and easier.