Need advice removing capacitor from ceramic substrate.

[rfdes]

I have a small ceramic hybrid with a suspect, leaky surface mount cap.  It appears like it was soldered using silver solder (it looks very shiny) but I'm not 100% sure.  The desire is to safely remove and replace this capacitor for testing and/or replacement.  I would appreciate any help in how to best approach this task.  My thought is to use hot air and paste as opposed to a solder iron and 15 mil solder (smallest I have).   I also don't know what the recommended temperatures should be used during the rework. This hybrid has no active parts, just passive parts and thick film trimmed resistors.  There are also some gold plated microwave structures.

I could use some advice from others with experience.
Thanks
Jim

[Swainster]

My experience with ceramic hybrids is that they are horrible to work on. The "tracks" appear to be more like conductive paint than copper foil, and will peel off as soon as you even look at them wrong. I was swapping a SO-8 transistor array in a TRMS converter, using a solder flood technique i.e. filling both sides of the SO-8 package with solder then removing the package while both blobs are still molten. I suspect that with the thermal conductivity of the (alumina?) substrate, this didn't work so well, hence a couple of the pads following the transistor array. Next time I do this, I intend to try using a plate to bring the whole hybrid up to temperature. Not sure what this will do to precision resistors though - nothing good I should imagine. Hot air seems like worth a try

[coppercone2]

can you grind it off with a smooth very fine diamond burr (thats placed against a diamond stone to get rid of high spots) and then solder over that ? with cooling