Swapped thermal grease on laptop cpu

[The_Document]

Was wondering if I applied a rather thick coat, would the excess just be squished out thus not hurting overal thermal conductivity severely? Idling at ~35°C is this temp good?

Used arctic silver 5 wanted liquid metal but I read the stuff drips and eventually leaks away also causing short circuits on the mobo.

[bunder]

It was tested that overdoing thermal paste usually accounts for 3-5c worth of temperature. An idle temp of 35c might be fine depending on what cpu you have.
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[The_Document]

It actually idles at ~32°C on low cpu clocks and I pressed down about 2.5mm on the syringe on a 3.5 gram tube of grease. I think it CAN be better if I redo it, but it seems fine and redoing it would really be a waste. Im sure the OEM grease was way worse anyways because there was a lot of it all around the CPU die, seems like they used too much and the thermal conductivity is probably way lower also.

[NeddySeagoon]

The_Document,

Thermal grease is a very poor thermal conductor but its a lot better that the air that would otherwise be in the gaps.

Here's the physics.
Two planes (the top of the CPU and bottom of the heat sink) can only ever touch at three points.
Consider how a three legged stool is unconditionally stable and a four legged chair will rock between several stable states.
Further, a 'point of contact' has a vanishing small surface area, so very little heat transfer can take place.

With two clean practical surfaces in contact, there is effectively a very small air gap.
Lets ignore the flatness for now except to say that minimising the air gap by improving flatness helps. You can't beat the three points of contact.

Thermal paste aims to replace the air in the gap with a material with better thermal properties.
When its applied as a 'sandwich filling', the original three point contact is lost and one poor thermal conductor is replaced by another.
It won't squeeze out enough, or it would run out over its intended useful life.

If you think you have put too much in, you probably did.
The right amount is no more than the size of a grain of rice.
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Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

[The_Document]

[Fitzcarraldo]

[P.Kosunen]

[Naib]

[The_Document]

[NeddySeagoon]

The_Document,

Too little is safer than too much thermal compound and CPUs have got bigger heat spreaders too.

Thermal compounds come in two sorts.
Those that set over the first few hours of use and those that don't.

It can be very difficult to separate the CPU and heatsink if you use the first sort.
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Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

[Naib]

[The_Document]

[Naib]

yup that is an IGBT module. Coincidently I am designing an inverter right now using SiC MOSFETS (TO247 package)
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#define HelloWorld int
#define Int main()
#define Return printf
#define Print return
#include <stdio>
HelloWorld Int {
Return("Hello, world!\n");
Print 0;

[The_Document]

[Naib]

The problem with JFET's is their "always on" default state. In the event of control powerloss OR failure of the gate PSU you are entering into shoot through territory. SiC MOSFETs are down in this ohmage as well so it is all good
_________________
#define HelloWorld int
#define Int main()
#define Return printf
#define Print return
#include <stdio>
HelloWorld Int {
Return("Hello, world!\n");
Print 0;

[The_Document]

[Goverp]

[Naib]

[The_Document]

Re did the thermal paste idling at 29C without X and 31C with KDE. I actually made it worse with Arctic Silver 5 because the temps were much higher a bit after applying idling at 41C, meaning I put too much, I put less than a size of a pea ammount of Thermal Grizzly Kryonaut paste, spreading it was very difficult. Works great.