Oxide on chip legs

Recently took some SMD chips out of storage, and noticed the legs have become quite dull. Solder will not adhere to them now, even acid fluxed.

Tried various metal cleaners, both soaking and ultrasonic bath.

Nothing seems to works.

Any suggestions ?

Thanks

Reply to
Minestorm
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That only leaves mechanical abrasion, which always works. A bit of fine emery paper would do it.

-- Bill Sloman, Nijmegen

Reply to
Bill Sloman

With that in mind, perhaps a Paasche Air Eraser would do the trick. It's basically an airbrush that has morphed into a small sand blaster. I'll bet it would do the job quite nicely. Perhaps not an optimal method if the OP doesn't already have access to an air compressor and also wouldn't have any other uses for the gizmo but, with the tool in hand, other uses may present themselves.

--
Rich Webb     Norfolk, VA
Reply to
Rich Webb

You can get a strong acid for darkening house bricks, I found a 5l bottle at the tip. It does for all those corroded things that just won't solder.

Watch out though - it strips the iron plating right off soldering iron tips.

Reply to
Ian Field

Brr...hope none of it diffuses through the epoxy! Abrasion for my money.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal
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Reply to
Phil Hobbs

Reminds me, I have a PBH2000 pencil blaster cabinet...

formatting link

Complete with "pencil", regulator, hoses, and fitted for shop vac dust collection. (And around 25# of very fine grit.)

I bought it around 6 years ago to do Girl Scout awards... etched glass mugs and plaques.

Our last granddaughter of that age just entered college, so no more Girl Scouts ;-)

Someone want it? Make me an offer.

Probably best for someone in Arizona or Southern California. It wouldn't be trivial to ship. It was originally shipped to me via truck. ...Jim Thompson

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| James E.Thompson, CTO                            |    mens     |
| Analog Innovations, Inc.                         |     et      |
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Reply to
Jim Thompson

Diluted HCL is pretty good. Use the swimming-pool stuff, diluted 5:1 or so. White vinegar works, too.

John

Reply to
John Larkin

Maybe something in the packaging outgassed; have you considered a degreaser or detergent in your ultrasonic cleaner, it might NOT be metal oxide at all. Metal oxide doesn't repel flux, in my experience.

Reply to
whit3rd

Jim, Looks interesting. How do you mask the object to be printed? Stencil cutter?

Charlie

Reply to
Charlie E.

Yep. I have a Stika SX-8 stencil cutter, apparently now called SV-8...

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I'm keeping it ;-) ...Jim Thompson

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| James E.Thompson, CTO                            |    mens     |
| Analog Innovations, Inc.                         |     et      |
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Reply to
Jim Thompson

That's not what they meant when they told you, "Make an outline, before you start writing". ;-)

--
You can't fix stupid. You can't even put a band-aid on it, because it's
Teflon coated.
Reply to
Michael A. Terrell

Scrub with flux pen?

Reply to
Robert Baer

I tried that, no effect

Tried ammonia, household detergent and vinegar

I have about 500 of them, so a chemical I can soak them all in would be really good.

Reply to
Minestorm

You can get a fiberglass abrading pencil, its like a propelling pencil but instead of lead it rolls out a bundle of fiberglass strands. They're generally used for copper tracks that got oxidised and won't solder - they'll take the solder resist off commercial PCBs with a bit of elbow grease.

Reply to
Ian Field

Are these something you can get another 500 of from Digi-Key or Newark or Future for cheap?

--
 - Don Klipstein (don@misty.com)
Reply to
Don Klipstein

Robert Baer wrote in news:zoudnTghMpIgp9jQnZ2dnUVZ snipped-for-privacy@posted.localnet:

Tarn-X?

--
Jim Yanik
jyanik
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Reply to
Jim Yanik
[snip]

Anyone want it? Otherwise to charity it goes. ...Jim Thompson

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| James E.Thompson, CTO                            |    mens     |
| Analog Innovations, Inc.                         |     et      |
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Reply to
Jim Thompson

"Jim Thompson" wrote in message news: snipped-for-privacy@4ax.com...

I don't want it, but I'm curious... what do you use for templates when making awards on glass? I mean, I can't imagine it looks good if you just try it freehand, does it?

Reply to
Joel Koltner

Well! As you all know... I'm a world-renowned artist ;-)

For more mundane things, you missed my comment...

"I have a Stika SX-8 stencil cutter, apparently now called SV-8...

formatting link

I'm keeping it" ...Jim Thompson

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| James E.Thompson, CTO                            |    mens     |
| Analog Innovations, Inc.                         |     et      |
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Reply to
Jim Thompson

Jim Thompson Inscribed thus:

Pity ! I'm on the wrong side of the puddle. :-)

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Best Regards:
                          Baron.
Reply to
Baron

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