Kapton Tape for Attaching Heat Sinks
Patrick, Sat Oct 25 2014, 07:34PMim thinking of using double sided tape to hold copper foil insulated via the kapton to an aluminum plate. im not sure if this is wise or possible.
the Kapton would be 2.7 mil for 1 mil of kapton. So i dont know if 1.4 mils of silicone adhesive on each side matters, but thickness worries me, as thermal resistance is non-linear with thickness right?
Re: Kapton Tape for Attaching Heat Sinks
klugesmith, Sun Oct 26 2014, 04:35AM
Nope, thermal conduction behaves like ohmic electrical conduction.
Resistance is proportional to thickness (length in direction of heat flow).
It's not hard to find the material properties (thermal conductivity) and run the numbers.
You might be interested in the results of an Internet search for Thermal Interface Material.
klugesmith, Sun Oct 26 2014, 04:35AM
Nope, thermal conduction behaves like ohmic electrical conduction.
Resistance is proportional to thickness (length in direction of heat flow).
It's not hard to find the material properties (thermal conductivity) and run the numbers.
You might be interested in the results of an Internet search for Thermal Interface Material.
Re: Kapton Tape for Attaching Heat Sinks
Nucleophobe, Sun Oct 26 2014, 05:32PM
Echoing the previous comment, this might help. The temperature profile through the solid is linear (conduction only), but through the fluid it is not (conduction plus convection).
Link with discussion:
Nucleophobe, Sun Oct 26 2014, 05:32PM
Echoing the previous comment, this might help. The temperature profile through the solid is linear (conduction only), but through the fluid it is not (conduction plus convection).
Link with discussion:
Re: Kapton Tape for Attaching Heat Sinks
Patrick, Mon Oct 27 2014, 04:41AM
ok so basically the thinner the better, and Kaptons' thermal resistivity im trying to find, but my internet connection is crap right now.
Patrick, Mon Oct 27 2014, 04:41AM
ok so basically the thinner the better, and Kaptons' thermal resistivity im trying to find, but my internet connection is crap right now.
Re: Kapton Tape for Attaching Heat Sinks
..., Mon Oct 27 2014, 05:48PM
I wouldn't recommend it for a really high performance application, but for light heat loads kapton is fine, and I have even seen it used in a few commercial products. I have seen the thermal conductivity specified as roughly 1W/m*k (compare to 30 for alumina, but keep in mind you can get away with a much thinner piece due to its better electrical/mechanical properties), although different brands will differ by about a factor of 2 or so. IIRC Dupont even makes a special 'high thermal conductivity' version for such applications.
One thing worth mentioning--1 mil layer of kapton, while specified to hold off about 5kv, will be very fragile and it is easy to poke a hole through it due to overtightening/spec of dust/etc. I have seen some products get around this by using 2 layers of kapton (by the looks of it, they just had the assembly line workers put 2 layers of kapton tape on the heatsink, then use a knife or drill to clear out the holes).
..., Mon Oct 27 2014, 05:48PM
I wouldn't recommend it for a really high performance application, but for light heat loads kapton is fine, and I have even seen it used in a few commercial products. I have seen the thermal conductivity specified as roughly 1W/m*k (compare to 30 for alumina, but keep in mind you can get away with a much thinner piece due to its better electrical/mechanical properties), although different brands will differ by about a factor of 2 or so. IIRC Dupont even makes a special 'high thermal conductivity' version for such applications.
One thing worth mentioning--1 mil layer of kapton, while specified to hold off about 5kv, will be very fragile and it is easy to poke a hole through it due to overtightening/spec of dust/etc. I have seen some products get around this by using 2 layers of kapton (by the looks of it, they just had the assembly line workers put 2 layers of kapton tape on the heatsink, then use a knife or drill to clear out the holes).
Re: Kapton Tape for Attaching Heat Sinks
Dago, Tue Oct 28 2014, 07:03AM
I think I've heard of someone commending kapton as being very good for this. Haven't tried it myself.
Dago, Tue Oct 28 2014, 07:03AM
I think I've heard of someone commending kapton as being very good for this. Haven't tried it myself.
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