Abstract: The present application describes a joining method of a Carbon Nanotube-assembly (1) on a substrate (2), showing a reproducible controlled joining with partly carbidization of the carbon nanotubes. To solve this problem, the Carbon Nanotube-assembly (1) is fixed to the substrate (2) by an active brazing process, with the steps of: melting and subsequent wetting and spreading of an active brazing alloy (3) in form of a at least ternary alloy, comprising an amount of copper and at least one carbide forming element with an amount of at least 1 wt % onto the substrate (2), contacting of the Carbon Nanotube-assembly (1) with the active brazing alloy (3) on the substrate (2), followed by a heating step of the components (1, 2, 3) in vacuum or inert gas atmosphere to temperatures above the solidus temperature of the active brazing alloy (3) and between 800° C. and 900° C. corresponding brazing material and assembly are also claimed.