The aluminum evaporation material shrinks when it is heated, but if it is heated directly, it will have a pinhole in it.
So I put it in a microwave oven for 500W.
When heat was applied to the CD in a microwave oven, the CD reacted in the same way as when electromagnetic waves were given to it, and it took on the appearance of space food, although it was not a vacuum.
The degree of shrinkage was about 10:8, and the reaction occurred instantly in about 3 or 4 seconds.
When heated for more than 6 or 7 seconds, a partial pinhole was found.