I was reading an article that Japan is experimenting with wooden chassis for satellites so that they can keep the trash minimal. I was wondering if it was possible to design the satellites in a way that no trash reaches the surface. Can they reach high enough velocity to completely disintegrate all the metal and plastic that would be left over after the exterior of the satellite is gone?
It's already the case that below a certain size of the satellite the probability of a sizable chunk reaching the surface is very low.
I used a search engine, using the search terms "satellite" "wood" to find your information source.
According to that information source the consideration is that some portion of the aluminium that goes into the satellite's frame will end up as fine dust; particles so small that they remain suspended in the atmosphere.
The idea of using wood, I infer, is to use a material that is bio-degradable.
Pollution of the atmosphere due to re-entry and disintegration (to dust) of satellites is a very, very small fraction of the total pollution burden.
To make some of the components of a satellite out of biodegradable material is more a sociological decision than an engineering/safety decision.
To make some of the components of a satellite out of bio-degradable material shows intent; it can serve as a message to the world.