Heatsink Fin to Base Thermal Resistance- Epoxy vs Braze
Heatsink Fin to Base Thermal Resistance- Epoxy vs Braze
(OP)
I'm investigating the trade-offs between bonding fins to a heatsink using thermally conductive epoxy or brazing. Epoxy is desirable because of cost but I need to quantify the impact on the thermal resistance of the fin-base interface. I can think of some basic hand calculations but I was wondering if there are any articles with correlations for this type of thing. I also need to find a thermally conductive epoxy that can withstand exposure to jet fuel and chemical solvents. Thanks.





RE: Heatsink Fin to Base Thermal Resistance- Epoxy vs Braze
TTFN
RE: Heatsink Fin to Base Thermal Resistance- Epoxy vs Braze
http://www.r-theta.com/
RE: Heatsink Fin to Base Thermal Resistance- Epoxy vs Braze
RE: Heatsink Fin to Base Thermal Resistance- Epoxy vs Braze
I'd also worry about finding an epoxy that will stay bonded through the required military range of storage and use temperatures, and thermal cycling.
I remember the US Navy as being very, very conservative about materials; will they even allow epoxy in this service?
Mike Halloran
Pembroke Pines, FL, USA
RE: Heatsink Fin to Base Thermal Resistance- Epoxy vs Braze
This thread is regarding a thermal / heat transfer question, the other is a materials compatibility issue. They are fundamentally different and each one lends itself to a different forum. Is there a better way to have handled this?
RE: Heatsink Fin to Base Thermal Resistance- Epoxy vs Braze
Thermal resistance R
Material thickness, L
Thermal conductivity, k
Cross sectional area, A
R = L/(k*A)
In order to make up for the lower thermal conductivity the epoxy will have to be much thinner, or over a larger area. Well designed brazed joints are .001/.002 thick, which makes it difficult to get the same preformance from epoxy.
Press fit fins are are another option. Conductive grease can be used and the interfernce fit will force it to very thin.
sreid's option also looks viable.
Matt Evans
Moorestown, NJ
RE: Heatsink Fin to Base Thermal Resistance- Epoxy vs Braze
In a heat sink