In the following picture
-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on
a
It was awkward getting the illumination angle right. The top one has a "silvery" coating to the pin and the bottom one a matt, "dusty" ie not metallic, light greyish, coating.
-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on
A silvery finish is associated with 60/40 type solder.
A dull finish is classic lead free.
Graham
Yes Rubycon is good qualty
Despite my belief that it was (self-repaired) punch-through of one of these Rubycon caps to cause an amp failure. I took each of these 470uF,50V to 55V on a ps with no hint of problem and didn't bother to discharge them. 3 days later I went to pack them away with lablels and the radial leads touched the tin they were temporarily in, a flash and a bang. The same with the other one when I tried it.
-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on
You asked before.
I'm not clear what it's supposed to show. It's not as clear as it could be for one thing.
Graham
from a
capacitor
for
I tried changing the angle of illumination and trying different colour backgrounds behind the pins but it was too difficult to differentiate with my camera and "techniques" . The bottom one came from a lead free soldered board. Instead of a "slivery" sweated film over the pins it was a dusty light grey (tin pest ? ) with just the odd small spot of "silvering". The top one was "good" overall "silvering" with just the presence of the normal lumps of old resin or whatever that is usually present on desoldering.
-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on
be
"slivery"
just
I think I'll have to dig out my viewing microscope/camera combo and redo the pic, I still have that cap laying around. I just tried finding a pic on the net of this dusty tin-pest ? surface but did not find one.
For those repairing stuff made before 2006 what is the method to best remove the tinning from the leads from modern replacements before using ? The distinguishing feature is that its much harder to abraid with a nail file/sandpaper than tradional Pb/Sn "tinning". It is one of my personal quirks to abraid all components ,ICs,trannies,R,Cs etc before soldering, as rarely new stock replacements.
-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on
from a
capacitor
for
I went back to the original unscaled image , although 2 cuts, they are from the same pic taken at the same time with the same illumination
-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on
The Commission naturally expected you to destroy all your old stock.
Graham
Yes, I can see the matt finish of the lead-free one now. That's how they're supposed to look AIUI.
Graham
I think if you dip the tin-plated wires in a sufficiently large quantity of sufficiently hot SnPb solder, that should mix pretty well with any tin plating that is already on the wires. The problem, as highlighted on the NASA pages is that you have to dip all the way up to the component body if you want to stop the tin whiskers, and that could damage metal-glass seals etc. as normally the soldering temperature is not supposed to be applied too close to the component body.
Of course, because that's how we save the environment, by creating extra waste and then manufacturing things we didn't need to.
That's why the WEEE was brought in after the RoHS, so that all of the old component stocks could all be landfilled or burned, while the component distributors rubbed their hands together with glee in anticipation of the new orders.
Chris
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