some paste for mounting diodes

[mottt]

i have to mount diodes on one generator rotor, and i remember some years ago to use some king of paste to mount them... to help to get a good contact areas between diode and plate..does somebody knows some manuefacturers of this paste

 

[ScumPunk]

Hi,
I think you are referring to Heatsink compound?
Like this:

http://uk.farnell.com/3821523/mechanical-office-workplace/product.us0?sku=servisol-200001002

It basically helps conduction of heat from the diode/transistor/whatever to the heatsink (in this case your generator).
Regards,
Mort

 

[eeinpa]

Most semiconductor devices are mounted using a silicone based grease, commonly called heatsink grease, heatsink compound, or thermal grease or compound.

Go to

http://www.digikey.com

and search for "thermal grease". Radio Schlock also used to carry it.

I'd apply it sparingly, as it gets soft when it is warm and it will fling off!

There are also a variety of silicone pads available which do a similar job while ALSO electrically insulating the device (which may not be desired!). These are commonly called "Sil Pads", which I believe is a brand name. Search digikey.com for "heat sink pads".

Good luck!

 

[itsmoked]

The intent of the stuff is to fill only the most microscopic of pores here or there. So a really really small amount should be used since you are aiming to fill voids in the 0.0001 arena under the mounting base.

Recently silicone based greases have fallen out of favor as they run/leak for months. So there are some that are not silicone based now too.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[itsmoked]

Example:

http://www.aavidthermalloy.com/products/options/greases.shtml

Keith Cress
kcress -

http://www.flaminsystems.com

 

[ScottyUK]

If these diodes are big hockey puck devices as I suspect then the grease is likely to be a metal loaded paste designed to give a uniformly good electrical and thermal connection to the heatsink. The alumina based pastes such as those listed above aren't so effective because alumina is a good electrical insulator even in thin films. There are a few varieties of the metal loaded pastes - we tend to use a busbar jointing paste such as Biccon X1.


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If we learn from our mistakes I'm getting a great education!

 

[LionelHutz]

I second what Scotty posted. Don't use any type of thermal heatsink compound on the puck type devices. Use a buss joint compound or failing that just clean the surfaces well and use nothing at all.

 

[electricuwe]

I agree to ScottyUK and LionelHutz - have seen some nicely burned presspack diodes after someone applied some of these white compounds intended for modules where noc electrical contact is needed.