Hi Inge!

Don't worry about sending me pictures to post on my web page, that's what it's for! Anytime you or anyone else want's a picture posted, just send em' my way!

Anyways, your pictures are up, and they are great pictures!

Go to: http://www.stevezeva.homestead.com and look at IMC_11 and IMC_11B.

These are photos of solder joints AFTER you did your process of degolding the leads? WOW! That close-up looks like something you see on the forest floor! It sure doesn't look like a very reliable joint...

Have you checked with any of the tinning shops that have robotic tinning machines to see if they can handle a component that small? Corfin Industries comes to mind:

http://www.corfin.net

-Steve Gregory

Hi. We call them so. Helicopters. Microwave SOTs with four wings. For teflon boards with hardback. Now, we've found that they are oftenly real gems, with up to 10 microns of gold from toe to knee. If they aren't degolded, you'll get IMCs en masse after soldering. The exteriour of such joints is well known: matte, greyish, prismatic, full of needles and plates. I've etched the surface of a typical one to demonstrate the joints interiour, see Steve's gallery.

MIL and SPACE have stringent requirements for soldering goldplated terminals, e.g. this typical one:

http://xweb.nrl.navy.mil/glast/CALDesign/CDE/CAL%20DPD%20Wire%20Cable%20Soldering%20and%20Staking%20Spec%20Rev%202.doc

Now to the practice. How on earth do you degold the legs on components that are not much bigger than what a fly leaves on your breakfast plate? Solder pot? Solder iron? Njet possible. Instead, we use to handsolder with a somewhat exaggerated amount of solder, then heat each leg separately and suck the solder with a Pace or similar, and then   resolder with fresh solder. Thus, we get rid of most of the gold-contaminated solder.

A'm curious about other's tricks. Anyone take the bate? Mr Creswick...ah..knew he couldn't resist...

Ingemar Hernefjord
Ericsson Microwave Systems

PS. Many SOT makers do not specify what gold thickness they have. Will be surprise...

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