Output power devices mounted directly on the metal case

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Hi ! i have this british amp with output devices mounted of the metal case that works as heathsink ... very british way
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in a word it looks quite messy
In a car audio amp i have seen this much more elegant solution with a thermal conductive sheet and a bar to keep the devices attached on the surface

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This solution among other things will allow for a easier removal of the entire board
I have spotted some bad solderings but i would like to work out of the case
Any suggestion ? Thanks a lot
gino
 

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Hi thanks for the very helpful advice A clamping bar could have just one screw ... it looks dirty
Do the electrical insulation sheets work well ? i also dont like the metallic screw
I have seen nylon ones but i am afraid they will crack with time
Moreover these mosfets are also mounted not aligned Unbelievable A good DIYer would do a so much better job that is unbelievable
I do not want to sound too critical but the design phase is a very important one The choice of layout ... thermal dissipation ... etc.
 
Agree, but don't think that neatness = best solution in all cases:

  • The unaligned FETs look messy but it has no impact on sound or thermal performance.
  • The metallic screws are perfectly safe if used correctly and nylon/POM screws can be damaged if tightend too much during mounting which leads to worse performance. The only exception for me would be HV applications, but this isn't one.
  • The mica + grease mounting is pretty much the best you can get (if done right) from a thermal POV, but because it takes much longer to do than thermal pads it was deemed to inefficient for mass production.
 
  • Thank You
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