with BeO, it has ecxellent thermal properties, bu it is dangerous. Normally you get it as ceramic sheets, hard, relatively brittle, and that is the point. If it worked on mechanically, drilling, grinding, sawing, or if it breaks, it generates ultra fine particles, that are most suspect to cause lung cancer when inhaled. This is why the material is banned from any electronic product in the US and the EU from 2006 on.
BeO sheets are made from powder which is pressed and sintered.
Replacement is AlN ( Aluminum Nitride ). Thermal conductivity 80% of BeO, about double thermal expansion coefficient. MAny sources, BeO is made worldwide exclusively by Brush-Wellman.
AlN materials are made from a paste which is rolled to thickness and the sintered.
Again, both materials are ceramics, completely unflexible.
The Kapton idea sound good, this will withstand te high temperatures, but getting hard and unflexibe when cold.
My suggestion is take a look at silcone rubber based heat transfer foils, as used in power electronics. Trade name is e.g. GRAFOIL. THis is flexible, lightweight, chemically inert, and comes in various modifications, with or without glass reinforcement, varois thicknesses etc.
It cannot be glued, but there should be ways to make the "bags" you need.
Hope this helps
Thomas
Price is coming to be equal for both materials. |
