I totally agree with the Metcal soldering station!!! I'll never go back to anything else. I don't even use a scope. I bought some magnifying glasses with 5 sets of different power lenses you wear like glasses. It has built in led light and adjustable strap that hold it on your head off Amazon. Works great. I can do all small surface mount stuff with them. Plus I have my normal vision and hand eye coordination going that way. Soldering under a scope or on a video monitor is a lesson all in itself!
Bill On Sat, Apr 25, 2020, 6:15 AM Gerhard Hoffmann <[email protected]> wrote: > > Am 25.04.20 um 13:41 schrieb John Ackermann: > > I do have a microscope (cheap Chinese unit, maybe $400 with articulated > arm and the works) and it does make things much easier. But as long as you > can see the work, you can do the job. > > > > It's not that hard to do small pitch parts. I usually do the best I can > soldering individual pins, knowing their will be bridges, then clean up > with solder wick and *lots* of no-clean flux. You can never have too much > flux. I've found a 1.6 mm chisel tip is a good all around size for SMD > work, though I have a 0.8 mm chisel available for when things get tight. > > > > The hardest part is getting the first couple of pins tacked down so the > part is square on the pads. After that it's fast. > > > > John > > I have about the same here, plus a cheap Chinese Ayoue852 hot air > station. Exchanging the Weller for a Metcal was the biggest improvement > after the LED ringlight for the microscope. > > In my quest to scrutinize the 1/f region, I have built some chopper > amplifiers and the newest one will have GaN transistors that are nekkid > chips with jut 4 tin bumps below. No case, just the passivated chip, 1 * > 1 mm, EPC2038. Low channel resistance, even lower capacitance -> low > charge injection. Resistors are 0603. > > Fearing I could not handle them, I made a minimum version of the switch > itself as a test structure in an unoccupied corner of a different > project. But soldering did take just 3 minutes, it was surprisingly > easy. Just keep the air flow low enough, or you will have trouble to > find the chips again. The thick-liquid flux helps to fix the chips in > place. > > Legible part numbers on the board are hopeless at this scale. The board > was made by PCBway, there were some discussions about having solder mask > ON part of the pads, and some discussions with our German customs that > you cannot buy 10 boards for $10 or so. > > The chips are the gray squares between the 2 vias on the left and the 4 > huge coupling capacitors. > > Cheers, Gerhard > > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
