I bought a bunch of MUR6030s for the quantity discount. I'm able to use them in a variety of applications without worrying about the voltage rating.
I see no downside to the higher voltage/current rated device except maybe voltage drop, for which I haven't noticed a difference.
Seems like Hags and I are in the minority with the sil-pad. My result when increasing the bias:
1.5v/.91=1.65A : 65C heatsink : 75C mosfet @1hr
In theory the sil-pad should be more effective than mica/goo or Al-Oxide pads/goo, but your actual mileage may vary.
I don't know about theory but I can tell you I got a little more heat transfer using the sil-pads than the alu-oxide with grease.
Like I said, if I had the sil-pads on hand at the time I would've used them. I didn't so I went with the alu-oxide.
Both work well IMO, I think the sil-pads work slightly better and I like to work with them more so than the grease.
Long ago in this HUGE thread, Nelson Pass stated that he uses Ultra fast diodes and prefers Mica for insulators.
NO, I don't remember which post #. LOL
Ron
NO, I don't remember which post #. LOL
Ron
There is a "mica and goo" thread somewhere here on the pass labs forum by papa, where he sums up his findings. AFAIK the result was that sil-pads were fine if the surface was flat, but mica and goo was better if there was surface was not perfect.
I remember NP's recommendation so I tried it, but instead of silicone goo I used artic silver. The heatsinks ran at 40-45C and didn't think about it for several weeks before checking the mosfet temps and they ranged from 100C to 120C! After removing them I could see that the artic silver did not spread evenly despite my best efforts. That's what I get for trying to be fancy and not using the regular grease which spreads better.
Bottom line is that contact area is perhaps more critical than thermal conductivity or thinness.
The sil-pads need to be torqued down to make sure there are no air pockets, so in this sense they are less forgiving than grease.
I think a common goo mistake is to apply too much - the thermal paste or goo is not supposed to do more than just fill out the cracks.
Here are some guides to apply paste to cpus - the theory applies equally to mosfets.
Arctic Silver Incorporated - Arctic Silver 5 Instructions
Here are some guides to apply paste to cpus - the theory applies equally to mosfets.
Arctic Silver Incorporated - Arctic Silver 5 Instructions
Yep, I remember seeing it. The MUR3060s are ultrafast diodes and I prefer the sil-pads for reasons already stated.
They both work and it boils down to a matter of preference.
Aawweee,
You beat me to it. I have seen this so many times repairing other peoples computers.....
Arctic Silver should be spread as thinly as possible with a brand new razor blade, if it gooshes out from underneath after mounting (CPU, Silpad, Mica) then too much was applied. It will prevent thermal dissapation, not encourage it. I love Arctic Silver when used in moderation.
I am using Silpads right now without any heatsink compound. 5 hours Idle time; Room temp 70*F, exterior heatsink temp 96*, interior Mosfet temp 110*, interior heatsink temp above Mosfet 108*. I have ordered large mica insulators and will change one channel using Arctic Silver and report on temperature changes (if any). Be about a week.
Ron
Papa also uses clips. A spring loaded clip is likely to move with the heating and cooling but maintain a more constant pressure over time. A torqued screw attachment may eventually squeeze out the goo, or even the pad, under hgh temp, then relax to less than the pre torqued pressure when things go back to normal 😱
Papa also uses clips. A spring loaded clip is likely to move with the heating and cooling but maintain a more constant pressure over time. A torqued screw attachment may eventually squeeze out the goo, or even the pad, under hgh temp, then relax to less than the pre torqued pressure when things go back to normal 😱
Ummm.
Looks like Papa uses the same as most of us; washer and lock nuts (aircraft nuts).
Ron
Attachments
Papa also uses clips. A spring loaded clip is likely to move with the heating and cooling but maintain a more constant pressure over time. A torqued screw attachment may eventually squeeze out the goo, or even the pad, under hgh temp, then relax to less than the pre torqued pressure when things go back to normal 😱
Agreed, however, the screws should be retorqued, and the bias checked and reset, after a few temperature cycles anyway.
I think I remember seeing the giant Pass monsters with sil-pads. Man, I love high quality!
Ok, its the Pass XA 30.5.
nope - if you use decent "security" washers ; dunno what's English word for these , but that's small spring steel washer , right under screw head