No mention of Deutsches Museum in Munich? Whaat!?

https://www.deutsches-museum.de/

Also recommended:

Arithmeum Bonn: https://www.arithmeum.uni-bonn.de/

Miniaturwunderland Hamburg: https://www.miniatur-wunderland.de/ (not really a tech museum but definitely of interest to techies)

In Switzerland:

Technorama in Winterthur: https://www.technorama.ch/

Verkehrshaus Luzern: https://www.verkehrshaus.ch/