I am using this https://www.amazon.de/tinker-integrierte-passivk%c3%bchlung-erforderlich-tinkerboard/dp/b07fmbrypy/ref=sr_1_1?__mk_de_de=%c3%85m%c3%85%c5%bd%c3%95%c3%91&keywords=alu+geh%c3%a4use+tinker+board&qid=1556780924&s=gateway&sr=8-1 Case without exceeding 43 Celsius.
By the way, LE Team do a great work. Thank you very much.