I have only removed the heatsink from an ignition amplifier and restored the thermal compound once. Less than a year later that ignition amplifier was the only one I have every had fail on amy of my Volvos.

I think that perhaps I did not apply enough compound and therefore did not have a good conduction of heat to the aluminum heat sink, but I am, as usual, clueless in these matters.

I used a compound from Radio Shack. I believe I allowed myself to be "upsold" by the clerk in that I purchased his suggestion of "Artic Silver 5" which the packaging claims as a "high density polysynthetic silver thermal compound". It must be used in the space shuttle as I remember it was very expensive.

I put a thin coating on the heatsink and the component and screwed it back together thinking what a great thing I had just done. Fast forward some months and I have a failed ignition amplifier.

On a recent trip to the U Pull and Pay I picked up another spare ignition amplifier and want to renew the compound. I have already pulled it apart and cleaned off the old dried up compound.

What is the correct amount of compound to put on the surfaces before reinstalling the screws? Do I need to apply enough to see evidence of contact between the two surfaces after application and pressing them together. I guess it makes sense to me that there should be no gap between the two surfaces.

Randy