Heatsink modding

[Scooby-Doo]

Thank you for your answer.

I agree that you can benefit by the bottom cover working as a large heatsink. This is what I have thought from the beginning. I just thought that if you use a large thermal pad, you close all the holes, so the heat of the bottom cover will have to dissipate through the air under the device going to the sides. If you use a small thermal pad under the processor and another one under the power unit, the heat is going to be transferred again to the bottom cover, but there will be air circulation through the holes, so the heat of the bottom cover can go upwards then sideways and create an internal wind stream which could enhance the total thermal behaviour.

Under any way, if I had to use a large thermal pad, I would cut it the Scooby-Doo way and not the robmich way which closes the gap between the two PCBs totally preventing air circulation. The edge of the thermal pad that is blocking the gap could be cut and probably be used over the smaller PCB, or not at all, since I do not think that this smaller PCB needs serious cooling.

O.k. now I understand you.

[Scooby-Doo]

Thank you for your answer.

I agree that you can benefit by the bottom cover working as a large heatsink. This is what I have thought from the beginning. I just thought that if you use a large thermal pad, you close all the holes, so the heat of the bottom cover will have to dissipate through the air under the device going to the sides. If you use a small thermal pad under the processor and another one under the power unit, the heat is going to be transferred again to the bottom cover, but there will be air circulation through the holes, so the heat of the bottom cover can go upwards then sideways and create an internal wind stream which could enhance the total thermal behaviour.

Under any way, if I had to use a large thermal pad, I would cut it the Scooby-Doo way and not the robmich way which closes the gap between the two PCBs totally preventing air circulation. The edge of the thermal pad that is blocking the gap could be cut and probably be used over the smaller PCB, or not at all, since I do not think that this smaller PCB needs serious cooling.

Here I have a proposal for you, if you want to improve the airflow.



The cooler might be expendable, because warm air rises.

[stevenjohns]

people keep mentioning thermal grease or thermal paste, i assume that its actually thermal adhesive that's required?

can i just avoid that and go for thermal tape? or 0.5mm thermal pads that are adhesive on both sides?

[SpoonThief]

people keep mentioning thermal grease or thermal paste, i assume that its actually thermal adhesive that's required?

can i just avoid that and go for thermal tape? or 0.5mm thermal pads that are adhesive on both sides?

I'm planning to use thermal tape for the heatsinks on top of the aluminum plate, I'll let you know how it goes once everything gets here.

[loko]

people keep mentioning thermal grease or thermal paste, i assume that its actually thermal adhesive that's required?

Thermal adhesive, whether it is paste or tape, is required when you want to glue two components together. If you want to attach an external heatsink to some component, and have no other way of securing it in place, you have to use thermal adhesive paste or tape, where the tape is easier to use and easier to remove but being a worse thermal conductor. That means that for permanent constructions, where thermal behaviour is critical, a thermal adhesive paste is preferred to a thermal adhesive tape.

If there is some mechanical connection between the two components, that holds them in place, thermal adhesive is not required and should not be used for two obvious reasons, the first one being that you will not be able to detach components easily without damaging them, and the second one being that thermal adhesives are worse thermal conductors than normal pastes. If the two components touch strongly each other you have to use normal thermal paste, but if there is a gap between the two components, you have to use a thermal pad. Since pads are worse thermal conductors than pastes, if you can close the gap and ensure strong pressure between the two components, it is better to use normal thermal paste, but if there is a gap anyway, you have to use a thermal pad to fill the gap. That means that for permanent constructions, where thermal behaviour is critical, modifying the construction to enable and ensure strong mechanical connection between the components, and using a good thermal adhesive paste, is the best solution available.

can i just avoid that and go for thermal tape? or 0.5mm thermal pads that are adhesive on both sides?

Thermal pads that are adhesive on both sides cannot replace thermal tape. The stickiness is required to hold the pad in its place, when there is probably not enough pressure over the gap to ensure that the pad will remain in its place even after being probably deformed after a long time of use, or if there are strong vibrations expected.

The thickness of a required thermal pad has only to do with the gap itself.

Thermal adhesive tape, on the other hand, is a totally different product.

[Scooby-Doo]

I wonder if that large bottom thermal pad everyone opted for is for good. There are many holes on the bottom cover, and using a large bottom thermal pad just closes them all, preventing free air flow. As we all know from computers, proper air flow inside the box is critical, and while some measure can help a component locally, it can have negative effects on the total results.

You can measure the bottom mainboard temperatures while stressing the unit. I bet under the power unit and probably under the processor the mainboard should be warm enough. Beyond these spots, I suppose most mainboard parts may be cool enough.

Would it be better to use a small square piece just under the power unit, and let the rest of the mainboard free, so the air can circulate freely around it? That would possibly let more cool air to enter the device and drift away more heat from the side holes.

Today I changed two of the screws of the case, which were loose with normal HDD screws. Now Everything fits again.

I took the chance for a modification of the setup: I put a smaller botttom pad 3x5 cm over the backside of the cpu and the power unit (same material, 5 mm thick).

Conclusion: I got the same temperatures like with the big pad. (35 ° C over all cpu cores before - 10 min. prime95 -> 46 ° C -> after 5 min. 36 ° C; ambient temperature = 22 ° C) Without pad the temps are 11/13° C higher and they need triple time to recover.

You can save money, with the same result!

P.s.: upload of pics is impossible at the moment.

[no_spam_for_me]

Which W/mK?
I only found 3x3cm and only 1.2 W/mK...

BTW:
Thermal Adhesive Paste
- Arctic Alumina (Ceramic)
or
- Arctic Silver
?

[Scooby-Doo]

Which W/mK?
I only found 3x3cm and only 1.2 W/mK...

BTW:
Thermal Adhesive Paste
- Arctic Alumina (Ceramic)
or
- Arctic Silver
?

5W/mK, I used the small part I cut out of the big blue pat. cut it into two pieces no it has together the described size. The big part I can use for other modding cases.

You can buy two pads like the one in the following link (in china you can order them cheaper)
Put the pads one beside the other over the parts I descibed. I think that would be big enough.

http://www.****.de/itm/EC-360-BLUE-5...item1c3eaf70cb

Maybe you search one 50x50x5 mm and you cut it. (5 w/mK is good 7 would be better. You don´t need thermal adhesive It´ll be pressed in and it´s a cooling pad.

[Pelliculart]

Today I changed two of the screws of the case, which were loose with normal HDD screws. Now Everything fits again.

I took the chance for a modification of the setup: I put a smaller botttom pad 3x5 cm over the backside of the cpu and the power unit (same material, 5 mm thick).

Conclusion: I got the same temperatures like with the big pad. (35 ° C over all cpu cores before - 10 min. prime95 -> 46 ° C -> after 5 min. 36 ° C; ambient temperature = 22 ° C) Without pad the temps are 11/13° C higher and they need triple time to recover.

You can save money, with the same result!

P.s.: upload of pics is impossible at the moment.

Oh yes, seem so good !
Sorry, my english is bad, hard to follow all conversation, can just just resume all product I need for a cheaper (from France) and easy modification to down the CPU temp like your new modification ? What I need ? (and did I need somethink like Artic Silver ?)

My Pipo X7 is like 45-60 in idle with 1,55 ghz, and 75-85°C in usage with flash videos for exemple (and frequency down like in 0,48 ghz). I don't understand because ambient temp like 19°C and I pose the Pipo in a cold and unstuck surface.

I need a modification to get down CPU temp, I think my stock thermal solution has a big problem :/

Hope I can see your picture soon

[Scooby-Doo]

Oh yes, seem so good !
Sorry, my english is bad, hard to follow all conversation, can just just resume all product I need for a cheaper (from France) and easy modification to down the CPU temp like your new modification ? What I need ? (and did I need somethink like Artic Silver ?)

My Pipo X7 is like 45-60 in idle with 1,55 ghz, and 75-85°C in usage with flash videos for exemple (and frequency down like in 0,48 ghz). I don't understand because ambient temp like 19°C and I pose the Pipo in a cold and unstuck surface.

I need a modification to get down CPU temp, I think my stock thermal solution has a big problem :/

Hope I can see your picture soon

Than explore this thread and decide wich other mods you will choose. The backside cooling pad is only reduces the tmp about 10 ° C alone.

[Scooby-Doo]

link deleted

[no_spam_for_me]

:
You don´t need thermal adhesive It´ll be pressed in and it´s a cooling pad.

No, I mean for the heatsinks...

[no_spam_for_me]

http://www.aliexpress.com/item/Free-...822191800.html

This one is cheap and you can decide, if you take the big or the little backplate pad solution. You can easily cut it in pieces.

http://www.aliexpress.com/item/Free-...822191800.html

Yes cheap BUT only 1.2 W/mK ...

[Pelliculart]

Yes cheap BUT only 1.2 W/mK ...

So you meen it's a bad efficacity ? Can you have a better suggestion of product ?
i don't want to use more than 15 dollars (shipping price include) to improve the Pipo thermal situation

[Scooby-Doo]

So you meen it's a bad efficacity ? Can you have a better suggestion of product ?
i don't want to use more than 15 dollars (shipping price include) to improve the Pipo thermal situation

Yes I saw that. My fault. Forget it. The other ones from post 128.

For the heatsinks I took Arctic silver two compound thermal adhesive.