How to install heat sink?

[gychang]

I plan to install gainclone chip on aluminum case using it as a sink.

One concern is to have a good conductance at the point of contact yet to avoid grounding issues. Not sure how it is done.

do I add a silicon thermal grease as in PC, CPU? and a screw?, but then it will conduct, nylon screw?, I see some amps have a "pad" inbetween.

can someone enlighten me on this?

 

[AndrewT]

For the TF version where the tab is insulated you can bolt using a steel screw (preferably with a washer) and just apply thermal goop between the tab and the sink.

For the T version where the tab is tinned copper you MUST insulate the steel fixing screw and insulate the heatsink.
Use a thermally conductive soft insulator between the tab and the sink.
Use a top hat plastic washer around the screw.
The narrow end of the top hat fits inside the tab hole. You must buy the correct size (for To220)
The wide side needs a load spreading washer under the screw head. Otherwise the washer deforms from the screw force and can eventually creep sufficiently to loosen the "grip" and overheat the chipamp.

 

[peranders]

Use the insulated TF package and some grease.

 

[gychang]

Use the insulated TF package and some grease.

thanks, now I know TF is the one I should use.

 

[SonyFan]

thanks, now I know TF is the one I should use.

Some companies call this "full pak" -- among other things. It's always the way to roll unless you have some specific need for the metal tab.

 

[AndrewT]

................... It's always the way to roll unless you have some specific need for the metal tab.

"always" really?

It has a significantly poorer Thermal performance than the T version.

 

[SonyFan]

"always" really?

It has a significantly poorer Thermal performance than the T version.

Some companies call this "full pak" -- among other things. It's always the way to roll unless you have some specific need for the metal tab.

Like thermal performance.