Re: Thermal Grease/Adhesive (?)

"Dave D" <dave_d@xxxxxxxxxx> wrote in
news:P7GdnZ6_aYjNkdbeRVnyjA@xxxxxxxxx:

>
> "CitizenRuth" <poopy@xxxxxxxxxx> wrote in message
> news:poopy-1D24EA.16183910102005@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
>>I needed to replace a switch on back of my HR824 powered speaker.
>> Behind the speaker is a metal enclosure which has power amplifiers
>> and other circuitry. After removing the main back metal enclosure, I
>> realized that the circuit board and heatsinks were attached to an
>> inner metal frame which was screwed to the outer frame. After
>> removing the screws, the thing wouldn't budge, until I realized it
>> was "glued" on and I was able to yank it off with some effort.
>>
>> The adhesive is white and greasy.
>
> What you have there is very common, it's just silicone heatsink
> compound, used to increase the efficiency of transfer of heat from
> component to heatsink. If it were thermal *adhesive*, they probably
> wouldn't have used screws to secure the assembly. Thermal adhesive is
> generally used instead of mechanical fixing methods, and the adhesive
> itself is rather pricey. It is very common for thermal heatsink
> compound to age and can become quite stubborn to break, which might
> lead one to believe it's adhesive, but it's easy to spot the
> difference as thermal heatsink compound will be softish and sticky as
> opposed to rock hard. Thermal adhesive is *very* sturdy though, it's
> epoxy based, sets rock hard and can require serious force to remove.



If the white compound had silicone grease in it,it would not dry out.
I believe the white compound has some other petro-based grease.


There is a silver-loaded thermal epoxy adhesive,and 3M(IIRC) makes a
thermal 2-part adhesive for gluing on heat sinks.

--
Jim Yanik
jyanik
at
kua.net
.

Relevant Pages

  • Re: PC still overheating???
    ... >underside of the heatsink has started to melt every so ... >contact with the heatsink. ... >small square of the compound missing from the middle, ... >where the raised section of the Athlon cpu touches the ...
    (microsoft.public.windowsxp.hardware)
  • Re: Thermal pads for transistor mounts
    ... My understanding is that thermal compound couples the bottom of the device to the heatsink by filling-in the tiny interstices that would otherwise exist between the slightly rough device and the slightly rough heatsink. ... My understanding was that silicon pads already have the optimum contact with both surfaces due to their squidginess. ... Putting 2 layers of thermal compound with less than 100% thermal conductivity between them is only going to make things worse. ...
    (rec.audio.tech)
  • Re: 360 Kaput! (Number 5)
    ... Well, happily, I was able to make a repair without too much difficulty ... heatsink compound being used on both the video and cpu chips. ... shortcircuited an IC and caused the 'no video output' problem. ...
    (alt.games.video.xbox)
  • Re: Help! Arctic Silver application....
    ... So, I took off the heatsink, ... > Should I try setting the heatsink under a lamp to warm up the compound, ... > so that it will easily spread? ... and that works much better than heating only the compound. ...
    (alt.comp.hardware.pc-homebuilt)
  • Re: AMD PIB - it does have a thermal pad, doesnt it?
    ... After replacing Peter Boulton with a small shell script on Saturday 26 Nov ... now have a silkscreened area of proper heatsink compound. ...
    (uk.comp.homebuilt)