A while ago, I have published an article about soldering fine pitch components.
It is still here.
But after a while, I found a better, faster and cleaner method, that I am going to illustrate
here.
Let's have a start!
Let's suppose that you have a PCB on which you want to solder a 0.5 mm pitch IC.
The following image is a gold-plated PCB.
Conver the pads with as much solder as they can handle
Now the first thing to do is to pour some solder on all the pads, so that their surface
cannot contain anymore. Seen from aside, it looks round shaped.
Component placement
Now place the IC. One important tip: Before opening the tray or desealing the
tape, put it as close as possible to the PCB. If you have one, use a small vacuum
tool as on this photograph.
Component position adjustment
Once it is roughly in place, adjust the position with the best tool ever invented:
your fingers. Without surhuman skills, you can adjust the position to +/- 0.02
or 0.03 mm. If the pin is roughly at the center of the pad, then it is fine.
Now hold it and heat one pin only at one corner.
Do the same at the opposite corner. At this point, since 2 pins only are soldered,
you can verify that the other pins positions are OK.
Soldering
When everything seems OK, you can heat the other pins 4 or 5 at a time by
pressing the pins to the PCB with the flat part of an iron without adding
solder, as illustrated here.
Inspection
Last, inpect the pins to make sure that they are all soldered.
That's it. No more desoldering tape, no more waste of solder. It's extremely
quick and a solder bridge remaining between 2 pins never happens.
That's your turn now. Have fun!
Pascal