So a couple of notes from here: I solder 0.5mm pitch TQFP's on a fairly regular basis with just a reasonably-sized chisel tip and plenty of flux. I often will end up with just a bit at the end of surplus which wick will pull off. I actually have done this on the bench with a $100 hakko FX601 and a questionable tip. So nothing to worry about.
As my eyes have aged, I don't see small things or far away things all that well. I have discovered a slightly overpowered set of reading glasses are perfectly adequate to look at a fine pitched TQFP to determine if there are bridges. I do have a couple stereo microscopes available to me, but I typically prefer the glasses unless I need to look very closely at the work. On Sun, Apr 26, 2020 at 12:28 AM Charles Steinmetz <[email protected]> wrote: > Burt wrote: > > > I have an AM-SCOPE 7-35 magnification stereo microscope. I also have an > > OptiVisor with a 5x stereo lens that my son gave me about 10 years ago. > > As nice as the microscope is, I generally wind up using the OptiVisor. > > Optics: > OptiVisors are *great*. But there are lots of poor-quality imitations > out there. Accept no substitutes! Buy Genuine Donegan OptiVisors > *only*, with "DA-" series glass lens plates (blue lens frames) -- *not* > the "LX" series with acrylic lenses in clear lens frames. > > The one drawback of OptiVisors is that if you want higher power you have > to settle for reduced working distance. At some point, I don't really > want my face that close to the hot iron and solder vapors. For > soldering, I find the DA-5 lens plate (2.5x at 8" working distance) is > my practical limit. A good stereo microscope (with reduced-power barlow > lens) solves this problem. > > BTW: Even 7x is *way* too much power for comfortable use as a soldering > magnifier, IMO. You might want to try a 0.2x to 0.3x Barlow lens, such > as the AmScope model SM03, which could make the experience much nicer. > And possibly some lower-power eyepieces. > > So: How about a wearable version of the stereo microscope (best of both > worlds)? > > Those are called "surgical loupes." And they are a pure joy to use. > Once you try a pair of properly fitted and collimated surgical loupes, > you will never go back to anything else for soldering small parts. > > However: surgical loupes are moderately to very expensive, and it's hard > to economize by buying used because they really need to be fitted and > adjusted by an optician who knows what (s)he is doing or you may have > eyestrain using them. If you are optically knowledgeable and can figure > out the misalignments for yourself (say, if you have sucessfully > collimated a few pairs of binoculars), it is possible to self-fit them. > *Note* that the collimation problem arises with stereo microscopes as > well -- many of the old venerable models you find used (B&L, AO) are > badly out of alignment. > > Soldering: > Finally, there is no need to flood IC pins with so much solder that you > need solder braid to remove it. The secrets are (1) use the right iron > tip (a flat or slightly concave bevel tip is one of the best, but a > spade will work); (2) keep the tip surgically clean; (3) keep the tip at > the right temperature; and (4) use quality solder with plenty of flux. > To see it done right (in less than 3-1/2 minutes), watch: > > <https://www.youtube.com/watch?v=5uiroWBkdFY> > > > Best regards, > > Charles > > > > _______________________________________________ > 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. > -- - Forrest _______________________________________________ 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.
