The present invention relates to method of manufacturing a fluid guiding assembly for a drug delivery device and to a respective fluid guiding assembly. Said method comprising the steps of : - providing a first member (12) having at least one recess (16, 18) in a first surface portion (22), - at least partially filling the recess (16, 18) with a joining component (26) at least partially protruding from the first surface portion (22) of the first member (12), - arranging a second member (20) having a second surface portion (24) adjacent to the first member (12) such that first and second surface portions (22, 24) thereof face towards each other to form an interface area (15) between the first and the second members (12, 20), - wherein the joining component comprises a material different to the material of the first and /or second member (12, 20) - wherein at least one channel structure (13) extending along the interface area (15) is formed by at least one deepening (14) of the first member (12) and/or of the second member (20), - selectively providing thermal energy to the joining component (26) to bond together first and second members (12, 20).La présente invention concerne un procédé de fabrication dun ensemble de guidage de médicament pour un dispositif dadministration de médicament et un ensemble de guidage de fluide respectif. Ledit procédé comprend les étapes consistant à : - se procurer un premier élément (12) ayant au moins une cavité (16, 18) dans une première partie de surface (22), - au moins partiellement remplir la cavité (16, 18) par un composant de jonction (26) faisant au moins partiellement saillie de la première partie de surface (22) du premier élément (12), - disposer un second élément (20) ayant une seconde partie de surface (24) adjacente au premier élément (12) de telle sorte que des première et seconde parties de surface (22, 24) de ceux-ci soient tournées lune vers lautre pour former une zone dinterface (15) entre les premier et second éléme