As far as I know, nearly all electronics manufacturers allow their printed circuit boards to be exposed inside their products. This allows ‘hackers’ to create and sell mod chips that circumvent digital rights management and use illegal pirated software. Instead of leaving the circuit exposed, they could create a sandwich layer boards that adhere to the circuit board with a thermal epoxy. To prevent heat buildup, the sandwich board would contain metal heatsinks embedded in it.

Of course, this adds additional costs to the product. It also creates a new point of failure in the manufacturing process. These two factors alone are probably the reason why we don’t see this idea implemented. In addition, it could make troubleshooting a defective product difficult, if not impossible.

In order to justify this idea, it would be necessary to estimate the lost revenue due to piracy created by exposed circuit boards. I suppose this idea is not cost effective in many situations.