[NLRS] Re: LFCSP (was re:power measurement)

[Doug Reed]

A quick comment here...
The description of a hot-air soldering tool is pretty accurate. It is 
just a heating element in a tube with a small air nozzle.

Caution, you don't need or want a high volume of air flow. Too much air 
will blow the pieces around. I tended to have better luck with a low 
volume of air that would be hotter and I could get right down on top of 
the part. You need enough air to heat the part and the solder paste but 
not so much you heat all the parts 1/4" around the target and blow them 
away.

I had the real tools at work but more than once I thought about trying 
to blow air through one of those bulb type solder-sucker irons just to 
see if it would work. I wasn't going to add any shield on the outside, 
just blow air through the center. I never did try it.....

At work we eventually all got away from hot-air techniques. It tended to 
be slow and had solder bridges just as often as hand soldering. And it 
was difficult to apply the correct amount of solder paste.

73, Doug Reed, N0NAS.


Dr. Gerald N. Johnson wrote:
> I've thought of a heat source for soldering these chip scale pieces to
> boards. Remember the solder sucker irons with a hollow tip. Put a
> ceramic sleeve around the outside for protection and blow dry air or dry
> nitrogen through the hollow tip. It should be hot enough to melt solder
> paste and so solder the chips to the board.
> 
> 73, Jerry, K0CQ
> 
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