Using a TO-220 heat sink

A

Adam Funk

Guest
Hi,

To attach an LM317 (for example) in the TO-220 format to the
corresponding heat sink (see link below), is it useful to apply any
thermal paste in addition to the flexible mat that comes with the heat
sink?

<https://www.aliexpress.com/item/VAKIND-10pcs-lot-Computer-Cooling-Accessories-Heatsink-Heat-Sink-With-Screw-Sets-15-20mm-For-TO/32802123591.html>

Thanks.


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On 26/04/2018 5:17 PM, Adam Funk wrote:
Hi,

To attach an LM317 (for example) in the TO-220 format to the
corresponding heat sink (see link below), is it useful to apply any
thermal paste in addition to the flexible mat that comes with the heat
sink?

https://www.aliexpress.com/item/VAKIND-10pcs-lot-Computer-Cooling-Accessories-Heatsink-Heat-Sink-With-Screw-Sets-15-20mm-For-TO/32802123591.html

Thanks.
Click to expand...

I would :)
 
On Thursday, April 26, 2018 at 5:30:07 AM UTC-4, Adam Funk wrote:
Hi,

To attach an LM317 (for example) in the TO-220 format to the
corresponding heat sink (see link below), is it useful to apply any
thermal paste in addition to the flexible mat that comes with the heat
sink?

https://www.aliexpress.com/item/VAKIND-10pcs-lot-Computer-Cooling-Accessories-Heatsink-Heat-Sink-With-Screw-Sets-15-20mm-For-TO/32802123591.html

Thanks.


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XML combines the efficiency of text files with the readability of
binary files.
Click to expand...

How much heat are you dissipating? (can you float the heat sink?)
I usually don't use any thermal paste with a sil pad.

George H.
 
On Thu, 26 Apr 2018 19:42:19 +0800, Rheilly Phoull wrote:

> I would :)

Me too. But only apply very, very sparingly.





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On 28/04/2018 3:50 AM, Cursitor Doom wrote:
On Thu, 26 Apr 2018 19:42:19 +0800, Rheilly Phoull wrote:

I would :)

Me too. But only apply very, very sparingly.
Click to expand...
Agreed, also I missed the power dissipation angle. If it was only low
power it's not worth the effort.
 
On Sat, 28 Apr 2018 08:37:21 +0800, Rheilly Phoull wrote:

On 28/04/2018 3:50 AM, Cursitor Doom wrote:
On Thu, 26 Apr 2018 19:42:19 +0800, Rheilly Phoull wrote:

I would :)

Me too. But only apply very, very sparingly.





Agreed, also I missed the power dissipation angle. If it was only low
power it's not worth the effort.
Click to expand...

Good point. If the load is light enough he doesn't need an additional
heat sink at all.





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This message may be freely reproduced without limit or charge only via
the Usenet protocol. Reproduction in whole or part through other
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On 04/26/18 05:17, Adam Funk wrote:
Hi,

To attach an LM317 (for example) in the TO-220 format to the
corresponding heat sink (see link below), is it useful to apply any
thermal paste in addition to the flexible mat that comes with the heat
sink?

https://www.aliexpress.com/item/VAKIND-10pcs-lot-Computer-Cooling-Accessories-Heatsink-Heat-Sink-With-Screw-Sets-15-20mm-For-TO/32802123591.html

Thanks.
Click to expand...

I'd compare it to a real silpad and see. If the pad itself has poor
thermal conductivity, grease won't help.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com
 
On 2018-04-26, Adam Funk <a24061@ducksburg.com> wrote:
Hi,

To attach an LM317 (for example) in the TO-220 format to the
corresponding heat sink (see link below), is it useful to apply any
thermal paste in addition to the flexible mat that comes with the heat
sink?

https://www.aliexpress.com/item/VAKIND-10pcs-lot-Computer-Cooling-Accessories-Heatsink-Heat-Sink-With-Screw-Sets-15-20mm-For-TO/32802123591.html
Click to expand...

I'd use paste only, unless an electrical connection between regulator
and heatsink would cause problems. That rubber stuff is for when you
need an insulator between the TO220 and the heatsink.

--
ŘŞ
 
On Sat, 28 Apr 2018 12:09:43 -0400, Phil Hobbs wrote:

I'd compare it to a real silpad and see. If the pad itself has poor
thermal conductivity, grease won't help.
Click to expand...

That's why I prefer the old mica pads.





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protocols constitutes acceptance of this condition.
 
On 04/29/18 10:19, Cursitor Doom wrote:
On Sat, 28 Apr 2018 12:09:43 -0400, Phil Hobbs wrote:

I'd compare it to a real silpad and see. If the pad itself has poor
thermal conductivity, grease won't help.

That's why I prefer the old mica pads.
Click to expand...

Mica is OK, and so is hard anodized aluminum plus grease.

Cheers

Phil Hobbs


--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com
 
On Sun, 29 Apr 2018 11:50:39 -0400, Phil Hobbs wrote:

On 04/29/18 10:19, Cursitor Doom wrote:
On Sat, 28 Apr 2018 12:09:43 -0400, Phil Hobbs wrote:

I'd compare it to a real silpad and see. If the pad itself has poor
thermal conductivity, grease won't help.

That's why I prefer the old mica pads.

Mica is OK, and so is hard anodized aluminum plus grease.
Click to expand...

Not if you need electrical isolation.




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This message may be freely reproduced without limit or charge only via
the Usenet protocol. Reproduction in whole or part through other
protocols, whether for profit or not, is conditional upon a charge of
GBP10.00 per reproduction. Publication in this manner via non-Usenet
protocols constitutes acceptance of this condition.
 
On 04/29/18 13:16, Cursitor Doom wrote:
On Sun, 29 Apr 2018 11:50:39 -0400, Phil Hobbs wrote:

On 04/29/18 10:19, Cursitor Doom wrote:
On Sat, 28 Apr 2018 12:09:43 -0400, Phil Hobbs wrote:

I'd compare it to a real silpad and see. If the pad itself has poor
thermal conductivity, grease won't help.

That's why I prefer the old mica pads.

Mica is OK, and so is hard anodized aluminum plus grease.

Not if you need electrical isolation.
Click to expand...

Works fine up to a few hundred volts--there are commercial thermal
insulators made that way. YCLIU.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com
 
In article <pc4ulb$5oo$25@dont-email.me>, curd@notformail.com says...
That's why I prefer the old mica pads.

Mica is OK, and so is hard anodized aluminum plus grease.

Not if you need electrical isolation.
Click to expand...

The only reason I know of to use mica or the anoidized aluminum plus
grease for them is when you need electrical isolation, otherwise just
use the grease or one of the rubber type pads. The pads are good for
isolation or heat transfer.
 
On 04/29/18 16:56, Ralph Mowery wrote:
In article <pc4ulb$5oo$25@dont-email.me>, curd@notformail.com says...
That's why I prefer the old mica pads.

Mica is OK, and so is hard anodized aluminum plus grease.

Not if you need electrical isolation.




The only reason I know of to use mica or the anoidized aluminum plus
grease for them is when you need electrical isolation, otherwise just
use the grease or one of the rubber type pads. The pads are good for
isolation or heat transfer.
Click to expand...
Hopefully both, but either way they're inferior to mica + good HS
grease. A lot cleaner and more convenient though!

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com
 
Rheilly Phoull wrote:

Me too. But only apply very, very sparingly.



Agreed, also I missed the power dissipation angle. If it was only low
power it's not worth the effort.
Click to expand...

** The TO220 heatsinks in the pic are only good for a couple of watts in free air - so device dissipation is low.

Device temp will only vary a few degrees using different mounting interfaces.


.... Phil
 
On 30/04/2018 1:40 PM, Phil Allison wrote:
Rheilly Phoull wrote:



Me too. But only apply very, very sparingly.



Agreed, also I missed the power dissipation angle. If it was only low
power it's not worth the effort.



** The TO220 heatsinks in the pic are only good for a couple of watts in free air - so device dissipation is low.

Device temp will only vary a few degrees using different mounting interfaces.


... Phil
Click to expand...
You are right of course, if it were I and there was sufficient clearance
there is no need for the insulation but there is scant info on the power
rating etc.
 
On Sunday, April 29, 2018 at 5:09:13 PM UTC-4, Phil Hobbs wrote:
On 04/29/18 16:56, Ralph Mowery wrote:
In article <pc4ulb$5oo$25@dont-email.me>, curd@notformail.com says...
That's why I prefer the old mica pads.

Mica is OK, and so is hard anodized aluminum plus grease.

Not if you need electrical isolation.




The only reason I know of to use mica or the anoidized aluminum plus
grease for them is when you need electrical isolation, otherwise just
use the grease or one of the rubber type pads. The pads are good for
isolation or heat transfer.

Hopefully both, but either way they're inferior to mica + good HS
grease. A lot cleaner and more convenient though!

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com
Click to expand...

Is mica any better than a sil pad? I thought it was worse.
I found this,
http://www.ti.com/lit/an/sboa020/sboa020.pdf
there's a table on page 2. But inconclusive... maybe mica is better.

George H.
 
In article <74c85a8b-ce6d-4723-80b4-e53995d9056e@googlegroups.com>,
gherold@teachspin.com says...
Is mica any better than a sil pad? I thought it was worse.
I found this,
http://www.ti.com/lit/an/sboa020/sboa020.pdf
there's a table on page 2. But inconclusive... maybe mica is better.
Click to expand...

It may depend on the type of pad. The best pads seem to be slightly
better than the mica/grease. They are almost the same,so I would guess
that whoever does the testing and maybe the material makes the
difference.
 
On Monday, April 30, 2018 at 1:02:40 PM UTC-4, Ralph Mowery wrote:
In article <74c85a8b-ce6d-4723-80b4-e53995d9056e@googlegroups.com>,
gherold@teachspin.com says...

Is mica any better than a sil pad? I thought it was worse.
I found this,
http://www.ti.com/lit/an/sboa020/sboa020.pdf
there's a table on page 2. But inconclusive... maybe mica is better.




It may depend on the type of pad. The best pads seem to be slightly
better than the mica/grease. They are almost the same,so I would guess
that whoever does the testing and maybe the material makes the
difference.
Click to expand...

OK the only thing I ever tested was a sil pad versus Kapton tape.
(TO-220) I didn't use any goop on the tape. (and it was tape with a
layer of adhesive on one side.) The sil pad worked better. I think it
was 1 mil tape (0.001"), but we have 2 mil tape too and it might have been
that.

George H.
 
In article <a9ac8b2f-d5d8-4059-88f5-3329fe7dbf3c@googlegroups.com>,
gherold@teachspin.com says...
OK the only thing I ever tested was a sil pad versus Kapton tape.
(TO-220) I didn't use any goop on the tape. (and it was tape with a
layer of adhesive on one side.) The sil pad worked better. I think it
was 1 mil tape (0.001"), but we have 2 mil tape too and it might have been
that.

George H.
Click to expand...

I thought Kapton was more of a heat insulator. I have only used it as a
heat shield when using the hot air wand on surface mounted devices so
don't know much about its properties.
 
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