Looking for ways to solder those ultra-fine pitch integrated circuit chips? Now, here’s a new nifty technique: drag soldering. The trick is to use a lot of flux, a fat soldering iron (yes. not a narrow tip one), and to drag the soldering iron lengthwise to maximize surface area back and forth across the pins. You want to coat with just the right amount of solder each time, not too much, and it will all work out, with the right amount of experimentation to learn the technique for different chips, that is.
20200514/https://68kmla.org/forums/index.php?/topic/59551-sram-for-portable-on-sale-at-digikey/
20200514/DuckDuckGo drag soldering
20200514/https://www.youtube.com/watch?v=wUyetZ5RtPs